Difference between references of Linux “utilities”, “commands” and “programs”

command lineterminologyUtilities

I read uses of the word "utilities" for commands/programs such as 'ls', 'chmod', 'mv', etc.

Is "commands" is Linux referring to the same things as top, ps, etc., or are those something different? What about "programs"? Are those the ones that don't come with the standard distribution which need to be installed like irssi, emacs, kismet, etc.?

Best Answer

This question is hard to answer, as there is no formal definitions of those terms and different people will use them differently. I here only give my use of them, others will have different points if view.

For me tool and utility are synonyms. I use the words for small programs which just do one small job. I'd call e.g. all applications implemented as applets in busybox tools or utility.

Any application is a program for me. I.e. 'ls' is a tool, a utility and a program. Firefox is a program but I wouldn't call it neither tool nor utility.