What's the binary file format used by MS DOS?

Question

I was always thinking MS DOS is also using PE for binary executable until recently when spotting this:

A PE image file begins with a MS DOS stub. It was used so that when a program is run in MS DOS, it would give a good error message (that the program must be run in windows) instead of crashing MS DOS.

So it implies PE isn't for MS DOS,then what is it?

Answer 1

COM and MZ.