This document provides an introduction to databases, database management systems (DBMS), and structured query language (SQL). It defines a database as a collection of organized information that can be quickly accessed by a computer program. Databases are created to store, manage, and retrieve large amounts of information. A DBMS is a software system that allows users and applications to define, create, query, update, and administer a database. Well-known DBMSs include MySQL, SQL Server, and Oracle. SQL is a standard language for accessing and manipulating data within databases and allows users to perform functions like querying, inserting, updating, and deleting records.