Each distribution of FreeBSD includes several documentation files describing the particular distribution (RELEASE, SNAPSHOTs, etc.). These files typically include:
README: General introduction.
Release Notes: Information about changes from the previous release of FreeBSD.
Hardware Notes: A list of hardware devices known to work with FreeBSD.
Installation Instructions: A brief guide to installing FreeBSD.
Errata: Late-breaking news, including corrections, security advisories, and potential problems found after each release.
The release notes, hardware notes, and installation instructions are customized for each architecture supported by FreeBSD.
RELEASE versions of FreeBSD
The release documentation for each -RELEASE version of FreeBSD (for example, 12.0-RELEASE) can be found on the releases page of the FreeBSD web site and on mirror sites.
These files are located in the top-level directory of each distribution. Both HTML and text forms are usually provided.
Snapshot Versions of FreeBSD
The release documentation files for snapshots are generally in the top-level directory of each snapshot.
Documentation for -CURRENT and -STABLE
HTML versions of the release documentation for FreeBSD -CURRENT and FreeBSD -STABLE are available on the FreeBSD web site. These documents are continually changing and automatically generated. The versions on the web site are rebuilt at the same time that the rest of the web site is updated.