UPM meaning in Computing ?

A man page (short for manual page) is a form of software documentation usually found on a Unix or Unix-like operating system. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts. A user may invoke a man page by issuing the man command.

By default, man typically uses a terminal pager program such as more or less to display its output.

Man pages are often referred to as an on-line or online form of software documentation, even though the man command does not require internet access, dating back to the times when printed out-of-band manuals were the norm.