SQL is a standard language for querying, manipulating, and defining data in databases. It allows users to retrieve, insert, update, and delete data as well as create databases and tables. Common SQL commands include SELECT, UPDATE, DELETE, INSERT, and WHERE. SQL databases also typically have proprietary extensions beyond the SQL standard. To build a website that displays database data, a developer needs an RDBMS database, a server-side scripting language like PHP, SQL, and HTML/CSS.