man - an interface to the system reference manuals
man [-k] [SECTION] PAGEOptions you will use
-k, apropos- Search the short descriptions for a keyword.
SECTION- 1 commands, 5 file formats, 8 admin commands.
-f- Like whatis: the one-line description of a page.
-k- Like apropos: search the descriptions.
Examples
$ man 5 systemd.servicethe unit file format, not the command
$ man -k timeranything with "timer" in its description
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