Strapi is an open-source headless content management system (CMS) that enables developers to build flexible and customizable APIs for managing digital content. "Headless" in this context means that Strapi provides the backend infrastructure for content management, but it doesn't dictate how the content is presented or displayed on the frontend. This allows developers to use any frontend technology or framework of their choice, giving them greater flexibility and control over the user interface.

Key features of Strapi CMS include:

Content Types: Developers can define custom content types and structures to suit the needs of their application. This includes defining fields such as text, date, media, and relationships between content types.

API-First Approach: Strapi is designed with an API-first approach, meaning that the API is the primary interface for managing and delivering content. This makes it easy to integrate with various frontend technologies, such as React, Angular, or Vue.js.

User Authentication and Permissions: Strapi provides built-in user authentication and role-based access control, allowing developers to manage user access and permissions to different parts of the system.

Plugins: Strapi supports a plugin system, which allows developers to extend and customize the CMS functionality. There are both community-contributed plugins and the ability to create custom plugins.

GraphQL and REST APIs: Strapi supports both GraphQL and REST APIs out of the box, giving developers flexibility in choosing the API technology that best fits their project requirements.

Admin Panel: Strapi comes with a built-in admin panel that provides a user-friendly interface for managing content and configurations.

Database Agnostic: Strapi is database-agnostic, meaning it can work with various databases like MongoDB, PostgreSQL, MySQL, and SQLite.

Developers often use Strapi to build scalable and customizable content management solutions for websites, mobile applications, and other digital experiences. It's popular for its ease of use, flexibility, and the ability to quickly set up a backend for content management without being tied to a specific frontend technology.