Changelog

A changelog answers the question 'what changed, and when?' for a piece of software. It is usually ordered newest-first and broken into sections such as Added, Changed, Deprecated, Removed, Fixed, and Security, with each release marked by its version number and date. The most widely used convention is Keep a Changelog, which standardizes those sections so readers always know where to look.

Changelogs commonly live in a CHANGELOG.md file at the root of a repository, where they double as the canonical history for developers. Many products also publish a hosted version of the changelog so customers and users can follow along without reading the source code.

While a changelog is comprehensive and tends toward terse, technical entries, it provides the raw material from which friendlier release notes are curated. Keeping the changelog accurate as changes merge makes writing user-facing announcements far easier later.