Clarification on the Purpose and Differences of Workplace Types in Creatio

In Creatio, what is the actual difference between the ‘General’, ‘Portal’, ‘Self-service’, and ‘Limited internal’ workplace types when creating a new workplace? All of them look identical in the UI, and I can’t see any functional distinctions.
Additionally, what is the purpose of the ‘Limited internal’ license, and is it directly related to the ‘Limited internal’ item shown in the interface on my screenshot?