By default, the access levels in Joomla are:
- public (everyone),
- registered (logged in users),
- special (authors and above).

However, you have the ability to create an infinite number of custom access levels to suit your site's needs.

Web accessibility, or eAccessibility, is the inclusive practice of ensuring there are no barriers that prevent interaction with, or access to, websites on the World Wide Web by people with physical disabilities, situational disabilities, and socio-economic restrictions on bandwidth and speed. When sites are correctly designed, developed and edited, more users have equal access to information and functionality.

Acronym of Access Control List, is a Joomla native function appeared in version 2.5 of the CMS which allows you to determine what each person can see and do on the site, both in backend and frontend.

A user with the administrator level on a Joomla site has access to all front-end and back-end functionalities.
Administrators are just below super administrators.

Alias are parts of text representing the title of certain elements (menu items, articles and category) and displayed in a format optimized for search engines. This format only allows numbers, lowercase letters and hyphens (-).

You can complete the "alias" field taking into account these limitations.
Alternatively, if you leave the "alias" field blank, Joomla will automatically generate an alias from the item title when saving. This implies that if you change the title of an element, while keeping the old alias, the alias (and the resulting URL) will not be changed.

If you want to generate a new alias, you must clear the content of the field.

AMP stands for Accelerated Mobile Pages.
It is an Open Source initiative launched in October 2015 which is mainly supported by Google, Twitter, Pinterest, LinkedIn, WordPress, Chartbeat, Parse.ly and Adobe Analytics.

Technically, AMP is a method of building web pages that helps display static content faster on mobile.

Apache denotes a popular web server. Apache is free software, distributed by the Apache Software Foundation which promotes various free and open source advanced web technologies.

An article is a piece of content on a Joomla! site. It can be composed of texts, images, videos...

An article is classified in a category and it is accessible from the "Content" menu then "Articles" of the administration panel.

A user with author level on a Joomla site can write and submit articles only from the frontend.

The back-end (or back-office, administration panel) is the part of a website or a computer system that is not accessible to end users or customers, as opposed to the front-end (or front office).

Process which makes it possible to save a complete (or partial) copy of the site in order to be able to restore it following, for example, hacking or improper manipulation. To fully back up a site, the process must integrate the database AND the files. It is strongly recommended that you back up your site regularly.

A blog is a type of website (or part of a website) used for the periodic and regular publication of articles, generally succinct, and reporting on news around a given subject or profession. . Like a logbook, these articles - or blog posts - are typically dated, signed and follow one another from the most recent to the oldest.

Bookmarks are the tabs stored in memory of a browser and allowing quick access to frequently visited web sites.

A bounce represents a visitor arriving on a website, and leaving it immediately, without having visited other pages on the website. Some bounces are inevitable on all websites, but an excessive bounce rate on a page probably indicates a problem and deserves special attention.

Breadcrumb is the path that shows the user the pages he has visited chronologically. This is displayed as: Home > category > page > page and each title is clickable.

Be careful, however, because the workflow can be based either on the path: "here is where you went", or on the structural reality of the site: "here is where you are on the site".

A byte is made up of 8 bits (eight 0s or 1s) and is used to store a character or an integer ranging from 0 to 255.

1 kilobyte (KB) = 1024 bytes,
1 megabyte (MB) = 1,048,576 bytes,
1 Gigabyte (GB) = 1,073,7418,244 bytes (2^30)

The cache is an intermediate memory system that makes it possible to display recently loaded web pages more quickly in the browser (a version of the visited page is saved in the form of temporary files on the computer and will be presented during a next visit , without having to wait for the response from the server).

Every part of Joomla powered web site or any CMS type of web site needs a method to display and store its content logically. The usual method is by categories and subcategories. Joomla allows for multiple ways to display and use content controlled by categorisation. Some of the content types which have categorisation are articles (Main content of web pages), banners, contacts and web links.

The visible graphical interface features of an application are sometimes referred to as chrome. See Applying custom module chrome for information about how to modify the look of modules (in other words, the module "chrome").

Acronym for "Content Managing System", a CMS is a website with publishing functionalities, a back-office, a workflow system allowing an editorial team to work simultaneously on the content of the site and a publication manager to validate the various contributions before they are put online. The articles and content of the site are stored in a database, while templates (page models) allow you to define the presentation of the content.

Components are the most important and complex extensions. These are the basic elements of Joomla. Most of them have a site part (frontend) and an administration part (backend). By default, Joomla is installed with a number of components that allow you to create your website: banners, contact cards, news feeds, web links, etc. Natively, the most important of them is "Content" which manages all Joomla content. A component is led by a menu link and brings important changes to Joomla by improving the native functions of the CMS.

Configuration.php is a file that stores all configuration settings for a Joomla web site.
This file is present at the root of all Joomla sites. All settings regarding the global configuration are stored as values in this file. This file is configured automatically during the Joomla installation process.

All text, image, sound and video files contained and displayed on a website.

A cookie is a very simple file, saved on the hard drive of the user's computer at the request of the server managing the website visited. It contains information on the navigation carried out on the pages of this site.

A Cascading Style Sheet or CSS is used to control the presentation of an XHTML page. For example, a CSS file will often control the font, margins, color, background graphics, and other aspects of a web page's appearance. CSS allows you to separate the content of an XHTML page from it's appearance. In Joomla!, CSS files (for example, template.css) are normally part of the template.

A database is an entity in which it is possible to store data in a structured way and with the least possible redundancy. This data must be able to be used by different programs or users.

The database table prefix is a string (a few characters long) prepended to the name of Joomla!'s tables. Using a prefix enables you to run multiple installations of Joomla! using a single database.

The database table prefix can be set during installation. Changing it later is possible, but requires access to the database through a non-Joomla medium or a Joomla Extension such as Akeeba Admin Tools and will cause some downtime.

Extension developers need to use the string #__ to represent the prefix. This will be replaced by the real prefix during runtime by Joomla.

The Domain Name System is a service that translates a domain name into information of several types associated with it, in particular into the IP addresses of the machine bearing this name.

The Domain Authority is a measure of a website's strength that determines its level of importance to search engines. On a basis of 0 to 100, a strong authority implies among other things, a better ranking in the search results.
This note is logarithmic; that is, it is easier to improve your authority by 10 points between 20 and 30 than between 70 and 80. In other words, the more your site gains in strength, the more difficult it becomes to improve your authority. In general, we consider that from an authority of 30 or more, it is a good start to implement SEO actions on the site.

A domain name is an internet domain identifier. It is composed of a name (google) and an extension (.com).

Action by which the user selects an object on the screen with the mouse pointer, moves it to another position while keeping the mouse button pressed, then releases it. This function is frequently used by photo, image or file manipulation components.

Duplicate content is being able to access the same content through several different URLs.
However, two types of duplicate content must be distinguished:

- external duplicate content: this is the content of a site that is totally or partially copied on another site,
- internal duplicate content: the same page of a website is accessible via several URLs.

An emailing is a personalized message sent electronically to a targeted audience to introduce them to a company, product or service. Emailing is now adapted to mobile technologies (Responsive Design).

Ergonomic designates the search for the quality of a site and a better adaptation between its functionalities and its users. Thus, when the site offers an easy and intuitive mode of navigation favoring a rapid handling of its functions, it is qualified as ergonomic. Ergonomics combines efficiency and comfort of use.

An extension is a program that adds more or less important functionalities to a website built on a CMS (Joomla, for example).

A Firewall is a software allowing to protect the elements of a network from the attacks of another network linked by a virtual gateway.

A footer designates the lower part of a web page that is generally found on all the pages of a website. Like the header, it is displayed on all pages of the website.

A forum is a discussion space with free access or reserved for a few participants. Discussions are archived there, which allows asynchronous communication (this is what differentiates forums from instant messaging). There are two types of forum: the "discussion forum" whose messages are classified by chronological date and the "question / answer forum" whose messages are classified by votes.

FOSS is the acronym for Free Open Source Software.
Software like Joomla! is FOSS because it is distributed for free use, copying, study, and modification. Free software usually uses a special software license, such as the GPL.

Freemium is an economic model for the sale of services which consists in attracting the prospect with a free offer in the hope of then making him switch to a paid offer to benefit from additional services.

As opposed to the backend (private part and administration of a website), the frontend is the part that is visible and accessible to all Internet users.

A Geek is a person with little social life due to his exaggerated passion for computers, new technologies, science fiction, or even video games.

A Giga is a prefix which, placed in front of the name of a unit, multiplies it by one billion (1,000,000,000).

Google is an American multinational company specializing in Internet-related products and services: online advertising, search engine, cloud hosting, software, etc. Most of its profits come from the AdWords service.
Link: www.google.com

GPL is the acronym for General Public License.
The most common license is the GNU General Public License, GNU GPL or GPL for short. This license is available in different versions and is used by Joomla and many other free software projects. Joomla is currently distributed under the GPL 2 license.

A hack is a modification of a core Joomla file (ie, all the files you downloaded before installing Joomla). Any changes to these core files will be overwritten with the next update. Also, modifications to the kernel files are really not recommended.

A hacker is a person who is endowed with highly developed knowledge of computers and new technologies. She will always seek to push the limits of the so-called "Impossible" to challenge secure systems, try to find the flaw that will make him the super-user of a remote system where he can draw the information he needs. A hacker does not destroy! It penetrates systems without destroying anything. He looks, he copies, he prints, he modifies (the "logs" in general) but he doesn't destroy anything.

The header designates the part of the site located at the very top, and which generally serves as the main menu, the logo, the title (as opposed to the footer).

A web host is a company that specializes in hosting websites on its servers. The host thus gives all Internet users access to the content deposited in their accounts by the webmasters, often via FTP software or a file manager.

HTML (or HyperText Markup Language) is a hypertext markup language (or markers). This means that we will manage the way a text will be displayed in the browser. Thus, we can see in any HTML source code compared to a text editor (like Word for the best known), striking differences, like tags (or markers) in the text of a web page.

HTTPS is the acronym for HyperText Transfer Protocol Secure, which can be translated as "secure hypertext transfer protocol". It is the combination of the HTTP protocol with an encryption layer of the TLS (Transport Layer Security) type – formerly SSL (Secure Socket Layer).

This protocol has become an SEO ranking signal for Google since August 2014: https://webmasters.googleblog.com/2014/08/https-as-ranking-signal.html

Also called attraction marketing, inbound marketing stems from a simple principle according to which prospects are attracted to you rather than seeking them out with traditional marketing techniques.

In SEO, indexing refers to the process by which a search engine lists the pages of the website it is analyzing, so that it can then display these pages in its results when a user's search matches. to the content of the pages in question.

Internet Explorer, sometimes abbreviated as IE, was the web browser developed by Microsoft and installed by default with Windows.
Between the end of the 1990s, when it dethroned Netscape Navigator, until around 2012, it was the most widely used web browser in the world. In 2014, it was second in Europe and third in France. Its main competitors are Mozilla Firefox (since 2004), Google Chrome (since 2008) and Safari.

Source: Wikipedia

An intranet designates an internal computer network that is developed within a company or organization and reserved for its employees, which operates with the same components as a web site. In general, an intranet allows employees to access internal resources (documents, discussion areas, training, etc.) of the company.

An IP address (with IP for Internet Protocol) is an identification number which is assigned permanently or temporarily to each device connected to a computer network using the Internet Protocol.

JavaScript is a programming language mainly used on the web. It allows you to offer a certain number of applications (display messages, modify the display of an element, the size of a window, etc.).

The Joomla Extensions Directory (more commonly known as JED) is the official Joomla website which lists several thousand extensions for Joomla (components, modules, plugins, etc). The templates are not listed there.

Joomla is a free, open source and free content management system (CMS). It is written in PHP and uses a MySQL database. Joomla includes features such as RSS feeds, news, printable pages, blogs, polls, searches. Joomla is distributed under the GNU GPL License.

The JoomlaDays are events organized annually by and for the Joomla Community worldwide.

History of JoomlaDays since 2005

LAMPP stands for Linux Apache MySQL Perl/ PHP/Python.
This group of Open Source programs are mainly used to run many dynamic websites. Most Joomla work under Apache and MySQL and all thanks to and with PHP.

A landing page refers to any page on which visitors arrive from an external site. In general, a landing page should be a page planned according to the origin of the visitors and optimized to correspond as much as possible to their particular expectations.

Languages are perhaps the most basic and critical extension type in Joomla. Languages are packaged as either a core language pack or an extension language pack. These packages consist of INI files which contain key/value pairs. These key/value pairs provide the translation of static text strings within Joomla! source code. This allows both the Joomla core and third party components and modules to be internationalised. Core language packs also include an XML meta file describing the language and providing information about the fonts to use for PDF content generation.

Linux is the name generally given to any free operating system running on the Linux kernel. This system was born from the encounter between the free software movement and the collaborative and decentralized development model via the Internet. Its name comes from the creator of the Linux kernel, Linus Torvalds.

The long tail is a concept used in SEO which was born from the observation that the quantity of visits coming from keywords varied constantly according to the more or less specific character of these keywords.

A manager is a level of access that can be granted to certain users on Joomla.
This level grants backend access and certain frontend privileges.

A media can be an image file, a video, a Flash animation or any document (Word, PDF, Excel) that we will include in the media manager (via the administration panel) and then insert it into the content writing.

In Joomla!, a menu is a set of menu items that are used for site navigation. Each menu item defines a URL to a page on your site, and settings that control the content and style (module(s), layout, etc.) of that page.
Also, each menu has a menu type, these are presented in the menu manager. Menu items can have a number of sub-items, called a "sub-menu".

A menu does not appear automatically. First you need to create a menu module to display the menu on all or some pages. Each menu can be represented by one or more modules. This allows the same menu to be displayed in different positions.

A menu that is not displayed by a module is generally called a "hidden menu" (or shadow menu). Hidden menus can be used to generate URLs that are not visible on a page.

Joomla makes extensive use of the Model-View-Controller design pattern.

When Joomla is started to process a request from a user, such as a GET for a particular page, or a POST containing form data, one of the first things that Joomla does is to analyse the URL to determine which component will be responsible for processing the request, and hand control over to that component.

If the component has been designed according to the MVC pattern, it will pass control to the controller. The controller is responsible for analysing the request and determining which model(s) will be needed to satisfy the request, and which view should be used to return the results back to the user.

The model encapsulates the data used by the component. In most cases this data will come from a database, either the Joomla database, or some external database, but it is also possible for the model to obtain data from other sources, such as via a web services API running on another server. The model is also responsible for updating the database where appropriate. The purpose of the model is to isolate the controller and view from the details of how data is obtained or amended.

The view is responsible for generating the output that gets sent to the browser by the component. It calls on the model for any information it needs and formats it appropriately. For example, a list of data items pulled from the model could be wrapped into an HTML table by the view.

A moderator is a person whose mission is to control and control the publication of messages on a website, a blog or a forum.

Modules are simpler and more flexible extensions, generally used to provide basic functions or improve the rendering of pages. Schematically, the modules are arranged around a component. By default, Joomla installs a number of modules, for example: login module, related articles, custom content module, etc. Modules are sometimes linked to components. They are assigned by menu items and can be displayed in any position of the template or even in an article.

Module Class Suffix is a parameter in Joomla! modules. It is set Module: [Edit] screen under Advanced Parameters. Setting this parameter causes Joomla! to either add a new CSS class or modify the existing CSS class for the div element for this specific module.

MySQL is a popular type of database that is distributed free of charge.
This type of database is very widely used in the creation of Web applications, most often in association with PHP.

Negative SEO consists of deliberately violating the guidelines of search engines concerning the optimization of natural referencing in order to reduce the ranking of a website (for example that of a competitor) in the results pages (SERP) .

A newsletter is advertising and/or information content sent by email on a regular or irregular basis to subscribers. The newsletter is one of the main interaction channels between a company and its prospects as part of an email marketing strategy.

Occurrence refers to the number of repetitions of the same word in a text.

As opposed to on-page SEO, off-page SEO designates all the factors for optimizing natural referencing in search engines that are external to the website.

These off-page factors are mainly composed by:
- incoming links to the site (called backlinks),
- social networks (Facebook, Twitter, Google+, LinkedIn, etc.),
- brand quotes on blogs, forums, in press releases, etc.

Unlike off-page SEO, on-page SEO refers to all the optimization criteria for natural referencing in search engines on which you can act directly: that is to say that they are directly editable from the site pages.

We distinguish here 2 kinds of criteria for on-page referencing:
- technical criteria: URL structure, HTML markup, internal linking, structured data formats, HTTPS protocol, etc...
- editorial criteria: the textual content, the optimization of this content according to your keywords, the titles of the pages, the description of the pages, etc...

A One Page web site is a website made up of one or a few pages (there is then a main page, the others being more or less “hidden”) used as part of a direct marketing strategy. Its goal is to direct visitors as much as possible, without any distractions (articles, links, advertising, etc.), towards the action you want them to perform: buy a product, register for a form , etc.

Software is said to be open source when the code is accessible and can be freely modified by anyone (as opposed to "proprietary code").

Opera is a free, cross-platform web browser developed by the Norwegian company Opera Software, which offers several Internet-related software.

Opera is a relatively underused browser compared to other web browsers, totaling around 5.5% market share according to StatCounter, and around 11.5% in the mobile environment. Since its version 15, Opera uses the Blink HTML rendering engine (against Presto previously).

Source:Wikipedia

options (also called "parameters") are parameters used to customize modules, components, plugins and templates. The basic extensions in Joomla offer many options that the site administrator can set to modify the behavior of the site without having any special programming knowledge.

Override is a technique that allows you to make changes to the visual aspect without modifying the original files. This prevents the modification from being overwritten during an update, for example.

Page Class Suffix is a parameter in Joomla! content menu items. It is set in a particular menu item: [Edit Menu Item] page, under the "Page Display" tab. A new page class suffix will cause Joomla! to either add a new CSS class or modify the existing CSS class for elements in the assigned to this very menu item page layout.

PageRank is one of the criteria used by a search engine to establish the positioning of a web page in its ranking. Its calculation is based on the number of external links that point to this web page. We are talking here about the quantity of links and not the quality of links. This is why this criterion is regularly called into question. It is to assess the reputation of sites that the Page rank was created by Google. It is a score ranging from 0 (the lowest) to 10 (theoretical maximum), and is intended to indicate the importance and credibility of a website.

A patch mainly refers to archive files that allow to upgrade a version of Joomla (for example, to switch from version 3.4.3 to version 3.4.5). In this case, we also speak of "update packages".

The permalink designates a hypertext link developed without limitation of time. It therefore prevents 404 errors.

Phishing is a fraud method that aims to impersonate a known person or entity. Most often practiced by email, the scammer pretends to be a bank in order to ask the victim to fill out a form to recover the account access data.

PHP (for "Hypertext PreProcessor") is a language that allows you to create dynamic web pages and scripts. In general, PHP most often takes the form of a series of instructions that are integrated into the HTML code of a web page, and which allow, for example, to create a registration form, a contact form, a survey, etc. .

Plugins are more complex extensions that manipulate a Joomla function (or component) before it is displayed. For example, the "Responsive Tables" plugin modifies the display of an HTML table created in Joomla in order to make it Responsive Design.

Popups are windows that open when browsing a website. They generally contain advertising messages, alerts, offers to subscribe to newsletters or any other type of content. Although they get bad press, it's a pretty effective web marketing tool if used sparingly.

A redirect is an instruction that consists in automatically (and transparently) redirecting the visitor and the search engines who wish to access a url A to a url B.
For example, if the user requests http://my-site.com, he will automatically be redirected to the address http://www.my-site.com, and this without any particular action on his part.

There are several types of redirects, mainly the 301 which permanently redirects traffic and the 302 which indicates a temporary redirect.

A 301 redirect strategy avoids losing a significant amount of traffic in the event of a website redesign.