Every change to a record is stored as a separate record version in DatoCMS.
RFC 4122 UUID of redord version expressed in URL-safe base64 format
"59JSonvYTCOUDz_b7_6hvA"
Must be exactly "item_version".
Date of record version creation
Whether the record version is the published version or not
Whether the record version is the most recent version or not
The entity (account/collaborator/access token/sso user) who made this change to the record
Whether the record version is valid or not
Validity of a version can only be established in the context of all the current or published item's versions (think about uniqueness validations, for example): use item's is_current_version_valid or is_published_version_valid fields instead.