Editions & Licensing
What each edition of MooseFS includes, and on what terms you may run it.
CE and PRO: feature matrix answers the first question. The matrix lists the capabilities one at a time and says which of them Community Edition includes and which belong to MooseFS PRO. The split is decided when the packages are built, so the matrix is also the list of decisions you cannot revisit later without reinstalling.
PRO Personal covers the tier a PRO installation starts on: what it permits, how much it allows, and where PRO Enterprise begins. How licensing works covers the terms themselves: the license Community Edition is distributed under, the license file a PRO cluster reads, and the limit that file sets. That page also covers what happens when a cluster reaches that limit or the license expires, and how a support contract relates to these terms.
Installing the license file is a procedure, so Deployment covers it. The page install a license says where the file goes and how a Master Server picks it up. Editions: Community and PRO defines the term "edition".