I’d say it gets a little different with command line utilities — maybe “utility” is the appropriate term here, but I’d call something like grep a program, not an application (again — “utility” also works).
To be sure, grep is extremely powerful, but its scope is limited.
Historically, an app is something with very limited uses, and a program is more powerful.
Adobe PhotoShop is a program. Apple Photos is an app.
I’d say it gets a little different with command line utilities — maybe “utility” is the appropriate term here, but I’d call something like
grepa program, not an application (again — “utility” also works).To be sure,
grepis extremely powerful, but its scope is limited.