In the 8086 architecture, which is the architecture that DOS targeted, memory references are composed of two parts: a 2-byte segment “identifier” and a 2-byte offset within the segment.

When the 8086 processor recovers from a hardware ... has to be a far jump to somewhere higher up in memory, and load the Code Segment and Instruction Pointer to the place where your program ...

The memory map of the original 8086 computer with its base and extended ... access to 16 MB on the 80286 and 4 GB on the 80386. The segment descriptors and resolving of these that make this ...