In order to run a Drupal site, the web server you are using must meet minimum technical requirements.
Patches are used to describe modifications made to one or more code files, and can be used to share those changes.
Modules are bundles of primarily PHP code that extend Drupal in order to add new features or alter existing functionality.
Theming Basics for Drupal 7
CourseResponsive Web Design
TopicResponsive web design is a set of design approaches and development best practices that ensures that a web design can be used on many types and sizes of devices.
Markup in Drupal 7
CoursePSD to Drupal 7 Theme
CourseLegacy Theme Development
GuideImage Styles
CoursePHP
TopicPHP: Hypertext Preprocessor (PHP) is a popular interpreted programming language that is especially suited for web development. Drupal core and all contributed modules are written in PHP.
Coding Standards in Drupal
CourseContributing to Drupal
TopicAs an open source project, Drupal depends on community contributions in many forms including documentation, code, translation, speaking, organizing events, mentoring others, and even donating money.
Hooks
TopicHooks allow modules to alter and extend the behavior of Drupal core, or another module. As a Drupal developer, understanding how to implement and invoke hooks is essential.
Blocks
TopicA block is a reusable widget that is placed inside regions (layout containers) of your theme. Blocks can be used by site administrators on the Block layout admin page or provided by a module using the Plugin API.
Layouts
TopicA layout can describe how various components are arranged on various levels—from an entire page from the header to the footer, to just the “middle” where the dynamic content goes, to individual components. It can apply to templates for managed content or one-off designs for landing pages.
Development environments provide a sandbox where you can work on your application without affecting the live site.
Back up Your Drupal Site
TopicA reliable backup will allow you to restore your site if something goes wrong.