<Tr> <Th> Type of format </Th> <Td> Executable </Td> </Tr> <Tr> <Th> Extended to </Th> <Td> DOS MZ executable </Td> </Tr> <P> A COM file is a type of simple executable file . On the Digital Equipment operating systems of the 1970s, . COM was used as a filename extension for text files containing commands to be issued to the operating system (similar to a batch file). With the introduction of CP / M (a microcomputer operating system), the type of files commonly associated with COM extension changed to that of executable files . This convention was later carried over to MS - DOS . Even when complemented by the more general . exe file format for executables, the compact COM files remained viable and frequently used in MS - DOS . </P> <P> The . COM 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 malicious computer virus writers . </P>

Com and exe files are examples of what type of files