PostgreSQL is a powerful, open-source object-relational database management system (ORDBMS) that extends the capabilities of traditional relational databases. Originally developed at the University of California, Berkeley in 1986 as the POSTGRES project, it has evolved into a robust, enterprise-grade database system. PostgreSQL uses SQL (Structured Query Language) for managing relational data, while also supporting advanced features such as JSON, XML, and key-value storage, enabling both relational and non-relational data management. One of PostgreSQL’s major strengths is its standards compliance and extensibility. It supports ACID transactions, ensuring data consistency, integrity, and reliability. Developers can define custom data types, operators, and functions, and even write code in languages such as PL/pgSQL, Python, Perl, and Java. Key features include multi-version concurrency control (MVCC) for high-performance concurrent access, foreign keys and constraints for relational integrity, and advanced indexing techniques such as B-tree, GIN, and GiST. PostgreSQL also supports replication, partitioning, and point-in-time recovery, making it suitable for enterprise and mission-critical applications.