MySQL is a widely-used open-source relational database management system (RDBMS) known for its simplicity, speed, and reliability. It is commonly used for web applications, content management systems, and e-commerce platforms. MySQL supports SQL for querying and managing structured data and offers features like replication and partitioning for scalability. It is compatible with popular web development stacks like LAMP (Linux, Apache, MySQL, PHP). MySQL is a go-to solution for small to medium-sized projects requiring efficient database management.