Ever wonder what a command you are using is? Turns out linux has the answers for you!
whatis followed by the name of the command.
$ whatis bc bc(1) - An arbitrary precision calculator language $ whatis brew brew(1) - The missing package manager for macOS brew-cask(1) - a friendly binary installer for macOS
whatis uses the man pages to search your entered query.
There is also a reverse search, which searches the descriptions of commands. For example say you are looking for a calculator:
$ apropos calculator bc(1) - An arbitrary precision calculator language dc(1) - an arbitrary precision calculator