Master is the latest stable release. Topics are branched from master. A release branch is master plus topics that are ready to go live. Releases are OS package

Master is the latest stable release. Topics are branched from master. A release branch is master plus topics that are ready to go live. Releases are OS packages (.deb, .rpm, whatever) built from release branches. We don't deploy with git because we don't commit binaries, and git doesn't know how to deploy our OS dependencies and drain and restart our prod services.