`whereis` is a tool used to locate binary, source and manual pages for a command.
whereis [option] [commandname]
[ -b ] :It searches for binary of command.
[ -s ] :It searches for source of command.
[ -m ] :It searches for manual of command.
[ -l ] :It output the effective lookup path for whereis.
You can find more on this tool in man page. `man whereis`