Editing MediaWiki Development Services (section)

== Definition and Core Concepts ==

=== What Is MediaWiki? ===

MediaWiki is a free, open-source wiki software package written primarily in '''PHP''' and using a relational database backend — most commonly MySQL or MariaDB — to store page content, revision history, user data, and metadata. It renders pages written in a lightweight markup language called '''Wikitext''' into HTML, which is then served to end users through a standard web browser.

The platform organises pages into '''namespaces''' — logical groupings such as Main (articles), Talk (discussion), User (personal pages), File (media), Template, and Help — each carrying different default permissions and display behaviours.

=== Key Terminology ===

{| class="wikitable sortable"
|+ MediaWiki Key Terms
! Term !! Definition
|-
| '''Namespace''' || A categorisation prefix that determines how a page is treated (e.g., <code>Template:</code>, <code>User:</code>, <code>File:</code>).
|-
| '''Extension''' || A plugin that adds or modifies MediaWiki functionality without altering core code.
|-
| '''Skin''' || A theme that controls the visual appearance and layout of the wiki interface.
|-
| '''Wikitext''' || MediaWiki's native markup language used to format page content.
|-
| '''Transclusion''' || The embedding of one page's content inside another, typically used with templates.
|-
| '''Revision history''' || A complete, immutable log of every edit made to a page, stored in the database.
|-
| '''LocalSettings.php''' || The primary configuration file for a MediaWiki installation.
|-
| '''Semantic MediaWiki (SMW)''' || An extension that adds structured, queryable properties to wiki pages.
|-
| '''WikiFarm''' || A server environment hosting multiple separate wikis from a single MediaWiki codebase.
|-
| '''ResourceLoader''' || MediaWiki's asset delivery framework for CSS and JavaScript modules.
|}

=== Fundamental Principles ===

MediaWiki is built on several foundational principles that distinguish it from general-purpose content management systems:

* '''Revision-based storage''' — every edit is stored with a timestamp and author attribution, enabling rollbacks, comparisons, and audit trails. No edit is ever permanently lost.
* '''Namespace architecture''' — a single installation serves multiple types of content with different access rules and display behaviours.
* '''Template transclusion''' — a single change to a shared template propagates automatically across hundreds or thousands of pages.
* '''Open extensibility''' — the Hooks API allows extensions to modify any part of MediaWiki's behaviour without patching core code.