PostgreSQL, or Postgres, is a mature, open source object-relational database management system software that is popular in enterprise and product applications.

Postgres has a number of advanced features over other RDBMS like MySQL which make it a good choice for large scale or mission critical applications.

It supports complex data types, and its Multi-Version Concurrency Control architecture assures data integrity. It adheres to ACID (Atomicity, Consistency, Isolation, and Durability) principles, and more closely follows the SQL standard dialect for queries.

For web application development, features like the ability to store objects with properties, like JSON and XML in the database can be useful. Likewise, the indexing tools in Postgres are useful for optimising views.