PostgreSQL, universally shortened to Postgres, is an open-source relational database known for standards compliance, extensibility, and correctness under concurrent load.

It began at UC Berkeley in 1986 as POSTGRES, a research successor to Ingres led by Michael Stonebraker. SQL support arrived in the mid-1990s and the project was renamed PostgreSQL to reflect it. Development has since been carried by a global volunteer community under a permissive license with no single corporate owner — a governance structure that has made it unusually resistant to the license changes and relicensing scares that have unsettled other open-source databases.

Technically it is distinguished by multi-version concurrency control, strict ACID guarantees, and an unusually rich native type system: JSONB, arrays, ranges, geometric types, and full-text search all live in the core rather than in a bolt-on. On top of that sits an extension mechanism that lets the database absorb entire adjacent categories — PostGIS for geospatial, pgvector for embedding search, TimescaleDB for time series.

That absorption is why Postgres became the default. A team that once would have run a relational database alongside a separate search engine and a separate vector store increasingly runs one Postgres instance instead, and managed offerings from RDS to Neon and Supabase removed the operational objection that used to push people toward simpler alternatives.