؟ What are the parts of ( UMA ) Upper Memory Area?

Short for Upper Memory Area, UMA is the area of RAM between 640KB and 1,024KB (1MB) that has been made into usable RAM. In DOS based systems, memory is split into five areas: conventional memory; upper memory; high memory; extended memory; and expanded memory. The UMA consists of upper memory blocks, and users can access this area through a special memory manager, such as EMM386.exe.