Editing COM file (section)

{{Short description|Type of simple executable file}}
{{Redirect|.COM|the top level Internet domain|.com|other uses|dot-com (disambiguation)|and|com (disambiguation)}}
{{Refimprove|date=February 2009}}
{{Use dmy dates|date=December 2021|cs1-dates=y}}
{{Use list-defined references|date=December 2021}}
{{Infobox file format
| name = COM
| extension = {{mono|.COM}}
| mime =
| owner =
| creatorcode =
| genre = [[Executable]]
| containerfor =
| containedby =
| extendedfrom =
| extendedto = [[DOS MZ executable]]
}}
[[File:IBM PC DOS 1.0 screenshot.png|thumb|A number of COM files in [[IBM PC DOS]] 1.0]] 
A '''COM file''' is a type of simple [[executable file]]. On the [[Digital Equipment Corporation]] (DEC) [[VAX]] [[operating system]]s of the 1970s, <code>.COM</code> was used as a [[filename extension]] for [[text file]]s containing commands to be issued to the operating system (similar to a [[batch file]]).<ref name="RT-11"/> With the introduction of [[Digital Research]]'s [[CP/M]] (a [[microcomputer]] operating system modeled after [[TOPS-10]] for the [[PDP-10]]), the type of files commonly associated with COM extension changed to that of executable files. This convention was later carried over to [[DOS]]. Even when complemented by the more general [[.exe|EXE]] [[file format]] for executables, the compact COM files remained viable and frequently used under DOS.

The <code>.COM</code> file name extension has no relation to the [[.com]] (for "commercial") top-level Internet domain name. However, this similarity in name has been exploited by [[malware]] writers.