This document provides an overview of SQL (Structured Query Language) including its history, purpose, basic components and syntax. It describes SQL as the most commonly used language for interacting with relational database management systems (RDBMS), including retrieving, manipulating and defining data. The summary covers the key elements of SQL like statements (DML, DDL), basic queries using SELECT, WHERE, ORDER BY, INSERT, UPDATE, DELETE, and creating/modifying tables. It also provides examples of SQL syntax for common queries and operations.