Extended Memory; Total Memory - Aaeon PCM-6896 Manual

Memory
You cannot change any values in the Memory fields; they are only
for your information. The fields show the total installed random
access memory (RAM) and amounts allocated to base memory,
extended memory, and other (high) memory. RAM is counted in
kilobytes (KB: approximately one thousand bytes) and megabytes
(MB: approximately one million bytes).
RAM is the computer's working memory, where the computer
stores programs and data currently being used, so they are
accessible to the CPU. Modern personal computers may contain up
to 64 MB, 128 MB, or more.
Base Memory
Base memory also called conventional memory is typically 640 KB .
The DOS operating system and conventional applications use this
area.

Extended Memory

Above the 1-MB boundary. Early IBM personal computers could
not use memory above 1 MB, but current PCs and their software
can use extended memory.

Total Memory

The section shows the total value of base memory and extended memory.
50 PCM-6896 User Manual