Let me tell you one thing very clear, both the terms that are SQL (Structured Query Language) and MySQL (Database Management system) are not the same.
Created in the 1970s by Chamberlin and Raymond Boyce, SQL is used in the manipulation and accessing of data in a database. It is basically used in querying data, updating data, controlling data access and during the creation and modification of schemas.
Whereas MySQL is a Relational Database Management System consisting SQL Server, Oracle, Informix, Postgres, etc. let me explain the term better with the help of an example.
When you as a user login the social sites such as Facebook, Flickr or YouTube using your login credentials, then the data is stored and logged in that site’s database using MySQL.
Both of these technologies use the table storage concept to store the data and thus keep it organized and readily available through a user interface.
Just the features and the syntax of the queries vary from one vendor to another.