Databases consist of software-based "containers" that are structured to collect and store information so users can retrieve, add, update or remove such information in an automatic fashion. Database programs are designed for users so that they can add or delete any information needed. The structure of a database is tabular, consisting of rows and columns of information.

Online Transaction Processing systems (OLTP) often use a "row oriented" or an "object oriented" data store architecture, whereas data-warehouse and other retrieval focused applications like BigTable, or bibliographic database (library catalog) systems may use a Column oriented DBMS architecture.

Document-Oriented,XML, knowledgebases, as well as frame databases and RDF-stores (also known as triple stores), may also use a combination of these architectures in their implementation.

Not all databases have or need a database schema ("schema-less databases").

Over many years [update] general-purpose database systems have dominated the database industry. These offer a wide range of functions, applicable to many, if not most circumstances in modern data processing. These have been enhanced with extensible datatypes (pioneered in the PostgreSQL project) to allow development of a very wide range of applications.