The binary format is most useful for bootloaders or DOS COM files, but may be used to create any binary format. See sample Win32_5, that demonstrates how the binary format is used to create a Win32 application.
If a listing file is produced, a binary map will be added, which shows the file and memory layout of the image:
.model tiny
.data
00000000 0D0A48656C6C6F2C20 str1 db 13,10,"Hello, world!",13,10,'$'
00000000 .code
org 100h
00000100 start:
00000100 B409 mov ah, 09h
00000102 BA0000 mov dx, offset str1
00000105 CD21 int 21h
00000107 B8004C mov ax, 4c00h
0000010A CD21 int 21h
end start
Binary Map:
Segment Pos(file) VA Size(fil) Size(mem)
---------------------------------------------------------------
_TEXT 0 100 C C
_DATA C 10C 12 12
---------------------------------------------------------------
1E 1E
Note that bytes with "undefined contents" at the start and the end of the output file are skipped and won't become part of the binary.