A database is a tool for collecting and organizing information in an organized manner. It allows data to be separated into different tables that can be merged together when needed. Microsoft Access is a database management system that allows users to add, edit, delete, organize and share data through its interface and various components like tables, forms, reports, and queries. The primary functions of a database are to store records of related data in tables, where each record is uniquely identified by a primary key and relationships can be created between tables using foreign keys.