FILE NAMES & EXTENSIONS

DOS : Filename.ext = 8 characters + . + 3 characters

WINDOWS : Filename.ext = up to 255 characters + . + 3 characters (sometimes 4 characters)

Examples:

Word.com Lotus.exe Jump.bat

Letter.txt contractA.doc Home Budget.123

Programs use the extensions BAT, COM, EXE, & CMD (BAT is not used much any more)

Program subrouotines use DLL, and many others too numerous to mention.

Data files of each specific program use a specific extension assigned to it.

For example:

M/S Word uses DOC (stands for document)

M/S Excel uses XLS (stands for excel)

Wordpad uses WRI and DOC (stands for write and document)

Notepad uses TXT (stands for text)

DLL stands for dynamic linked library

ZIP represents a compressed file using a particular coding.

CAB stands for cabinet file and usually contains many compressed files.

INI stands for initialization file.

CFG stands for configuration file.

And there are many more!

Windows associates data files with specific programs by looking at the file’s extension. Changing a file’s extension can render it inoperable, but it can be changed back. Windows Explorer(not Internet Explorer) is the file manager program used by Windows and can change both file names and extensions. This action is called “renaming” a file.