MySQL is an open-source relational database management system (RDBMS) that is widely used for managing and storing data. It is one of the most popular database systems and is known for its reliability, scalability, and ease of use. MySQL uses Structured Query Language (SQL) as its language for interacting with the database. SQL is a standard language for managing relational databases, and it allows users to perform various operations such as creating, modifying, and querying databases.