From mediawiki.org
Wiki entity
Something on-wiki which will be judged. Note that we make a distinction between two aspects of wiki edit: its "diff" and its snapshot which we call a "revision". A diff is the changes made, which might be damaging or good-faith. A revision is the article's content after an edit. In the future, other wiki entities may be judged, for example specific, logged admin actions.
Entity page
Judgments about a wiki entity will be stored on a page with a title identifying the entity. E.g., "Jade:Diff/123456" represent an edit entity. The page contains many labels groups.
For any given entity, there are different judgments that can be applied. Each judgment refers to some facet/aspect of the entity. E.g. What quality is this edit? What kind of change did the edit make? What quality level is this article version? What's the topical coverage of this page? A facet is defined by a label schema and a set of proposals about which label is the Right(TM) label for the target entity.
Label schema
Concrete scale on which a proposed label is defined. This can be as simple as the answer to a yes/no question, "Q: Is this edit damaging? A: Yes.", or might allow several possible values such as one choice of "featured article", "good article", "stub article", "C", "B", or "A".
Proposal (AKA "proposed label")
A proposed label about a wiki entity. A proposal contains data that corresponds to a label schema and notes about why the that data applies. E.g. This edit is "damaging" because "keymash". A proposal also contains a (possibly empty) set of endorsements from editors who agree that the proposed label is Right(TM). The consensus proposal can be flagged as "preferred". Only exactly proposal per proposal group can be marked "preferred". No two proposals can have identical data.
Proposal notes
Explains a proposed label. The notes can be edited by anyone. Wikitext is allowed. E.g., "#keymash and #slur, [[WP:NONSENSE]]"
Editors post an endorsement for proposal they support. An endorsement has an author and is generally not editable by other editors. Endorsements should not be tallied like votes, the "preferred" label proposal is the correct one. But endorsements allow editors to file disagreement/agreement along with their reasoning in the form of an endorsement comment. An editor can only endorse one proposal within a proposal group.
Endorsement comment
Usually this will be the endorsing editor's reasoning for agreeing with a proposal. Wikitext is allowed. E.g., "per [[WP:BLP]]"
Entity talk page
Each entity page can have a corresponding Talk page, where possible labels are discussed and agreement is formed. E.g., "Jade_talk:Diff/123456" contains freeform discussion of potential labels for the edit that created revision 123456.