PostgreSQL is a general purpose and object-relational database management system, the most advanced open source database system. 

PostgreSQL was designed to run on UNIX-like platforms. However, PostgreSQL was then also designed to be portable so that it could run on various platforms such as Mac OS X, Solaris, and Windows.

PostgreSQL is free and open source software.

Why use PostgreSQL?

PostgreSQL comes with many features aimed to help developers build applications, administrators to protect data integrity and build fault-tolerant environments, and help you manage your data no matter how big or small the dataset.

Key Features of PostgreSQL

PostgreSQL offers many features that

• User-defined types
• Table inheritance
• Sophisticated locking mechanism
• Foreign key referential integrity
• Views, rules, subquery
• Nested transactions (savepoints)
• Multi-version concurrency control (MVCC)
• Asynchronous replication

What makes PostgreSQL stand out

PostgreSQL allows you to add custom functions developed using different programming languages such as C/C++, Java, etc.

PostgreSQL is designed to be extensible. You can define your own data types, index types, functional languages, etc. If you don’t like any part of the system, you can always develop a custom plugin to enhance it to meet your requirements e.g., adding a new optimizer.