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, 12.2-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.