---
title: "What Is PostgreSQL?"
id: intro-whatis
pg_version: "20devel"
---

<a id="intro-whatis"></a>

## 1.  What Is PostgreSQL?

PostgreSQL is an object-relational database management system (ORDBMS) based on [POSTGRES, Version 4.2](https://dsf.berkeley.edu/postgres.html), developed at the University of California at Berkeley Computer Science Department. POSTGRES pioneered many concepts that only became available in some commercial database systems much later. 

PostgreSQL is an open-source descendant of this original Berkeley code. It supports a large part of the SQL standard and offers many modern features: 
- [complex queries](sql.md)
- [foreign keys](ddl-constraints.md#ddl-constraints-fk)
- [triggers](triggers.md)
- [updatable views](sql-createview.md#sql-createview-updatable-views)
- [transactional integrity](transaction-iso.md)
- [multiversion concurrency control](mvcc.md)

 Also, PostgreSQL can be extended by the user in many ways, for example by adding new 
- [data types](datatype.md)
- [functions](functions.md)
- [operators](functions.md)
- [aggregate functions](functions-aggregate.md)
- [index methods](indexes.md)
- [procedural languages](server-programming.md)

 

And because of the liberal license, PostgreSQL can be used, modified, and distributed by anyone free of charge for any purpose, be it private, commercial, or academic.