PostgreSQL Introduction

PostgreSQL (often shortened to “Postgres”) is a powerful, open-source object-relational database system with over 35 years of active development behind it. It started life as a research project at the University of California, Berkeley in the 1980s, and has since grown into one of the most trusted, feature-rich databases in the world — used by companies of every size, from one-person side projects to organizations like Apple, Instagram, and Spotify.

You will frequently hear PostgreSQL described as “the world’s most advanced open source database.” That is not just marketing — it reflects a genuine reputation for strict standards compliance, rock-solid data integrity, and a feature set that rivals (and in many areas exceeds) expensive commercial database systems, all while remaining completely free and permissively licensed.

What can you build with it?

PostgreSQL is a general-purpose database, which means it is a solid choice for almost any application that needs to store and query structured data reliably:

Web and mobile application backends — user accounts, orders, content, sessions
Analytics and reporting systems — thanks to rich aggregation, window functions, and JSON support
Geospatial applications — via the PostGIS extension, used heavily in mapping and logistics
Financial and transactional systems — where strict data integrity (ACID guarantees) is non-negotiable
Full-text search and document storage — using native full-text search and the JSONB data type

A quick taste

PostgreSQL speaks standard SQL, so if you have ever queried any relational database before, this will look familiar. Here is a simple query against a table of products:

A first SELECT query

SQL

SELECT name, price
FROM products
WHERE price > 50
ORDER BY price DESC;

That statement asks PostgreSQL for the name and price of every product priced above 50, sorted from most to least expensive. Simple queries like this are the building blocks for everything else you will learn in this series — filtering, joining, aggregating, and eventually designing entire database schemas from scratch.

Why this tutorial series exists

This series walks through PostgreSQL from the ground up: installing it, connecting to it, modeling data with it, querying it efficiently, and eventually administering it in production. Every page includes runnable SQL examples so you can follow along on your own machine.

No prior database experience required

We will introduce concepts like tables, rows, and columns as we go. If you already know another database system, you will find most of your knowledge transfers directly — PostgreSQL is standards-compliant SQL with some genuinely useful extras layered on top.

Tip

Keep a PostgreSQL instance handy while you read. The Installing PostgreSQL and Setting Up a Sample Database pages later in this series will get you a working local database in a few minutes.