Introduction to WordPress

WordPress is a free, open-source platform for building websites. More technically, WordPress is a content management system (CMS) written in PHP and using a MySQL database. In non-technical terms, WordPress is the easiest and most powerful blog and website builder available today.

WordPress is an excellent platform for creating all kinds of websites. From blogs to e-commerce sites.

Download

• Latest WordPress (eng.): https://wordpress.org/latest.zip
• Latest WordPress (ru.): https://ru.wordpress.org/latest-ru_RU.zip
• https://wordpress.org/download/releases/ - all versions releases.

Requirements

Recommended:

• PHP 8.3+
• MySQL 8.0+ or MariaDB 10.6+
• HTTPS
• Apache or Nginx (recommended)

Minimum:

• PHP 7.2.24+
• MySQL 5.5.5+
• Any server supporting PHP and MySQL

Source: https://github.com/WordPress/WordPress/blob/master/wp-includes/version.php

More details: https://wordpress.org/about/requirements/

Source code

• WP core code: https://github.com/WordPress/WordPress

• WP developers repository: https://github.com/WordPress/wordpress-develop

• Code for all WordPress versions: https://build.trac.wordpress.org/browser/tags/

• Source code of WP plugin directory: https://plugins.svn.wordpress.org/

• core.trac.wordpress.org — WP core code of the latest version (including alpha and beta). But it’s more convenient to view it on github (link above).

Getting started with WordPress

• WordPress usage statistics
• Features of WordPress
• WordPress terminology (glossary)
• WordPress support forum

Working with WordPress

• Installing WordPress
• Updating WordPress
• WordPress for beginners — Where to start
• Template hierarchy
• The WordPress Loop
• Template tags (theory)
• Function list (template tags)
• Function list
• Creating a database backup

API in WordPress

• Meta boxes API (Widgets API). See the add_meta_box() function.
• HTTP API
• REST API
• Plugins API. Also read about hooks.
• Shortcodes API
• Theme Modification API
• Sitemap API
• Customizer API (Theme Customization API)
• Widgets API. Also read the article from the official site (eng.)
• Translations API (localization)
• Rewrite API. Also read the description of the WP_Rewrite class (there are many examples there).
• File Header API
• Filesystem API. See the API functions.
• Quicktags API (HTML editor buttons)
• Heartbeat API
• Object cache API (object cache)
• Cron API (cron task scheduler)
• Robots API
• For the database:
  • Database communication API (wpdb class)
  • Settings API
  • Options API
  • Transients API
  • Metadata API

Cheat sheets