A unit of output it 2sxc is called a Block. In Dnn-Link, this can be like a Module, except that blocks can be inside other blocks.
Looking at it from the Platform like Dnn, the entry object is an ICmsBlock which contains context information (in Dnn's case, ModuleId etc.). Inside it is an IBlock which can itself contain more IBlocks.
Note that each Block itself has Views and data specific to that block.