Developers can create custom themes by designing templates, styling with CSS, and using PHP to integrate dynamic content.
Plugins extend the functionality of WordPress. Developers can build custom plugins to add features such as contact forms, SEO tools, or integrations with third-party services. The WordPress Plugin API simplifies the process of creating and managing plugins.
The WordPress REST API allows developers to interact with WordPress data programmatically. This is particularly useful for building headless WordPress applications or integrating WordPress with external systems.