We used to refer to .com files as memory images, because they look the same on disk as they do in memory. EXE, OVL and the like had relocatable segments, where

We used to refer to .com files as memory images, because they look the same on disk as they do in memory. EXE, OVL and the like had relocatable segments, whereas the memory images assumed all segments were within the code segment. cs=ds=es and the stack you just crammed somewhere in that space, usually at the end of the literal code, but still very much inside the space of the one segment you could access.