apropos-command is an interactive autoloaded compiled Lisp function in `apropos.el'.

It is bound to C-h a, <f1> a, <help> a, <menu-bar> <help-menu> <search-documentation> <find-commands-by-name>.

(apropos-command PATTERN &optional DO-ALL VAR-PREDICATE)

Show commands (interactively callable functions) that match PATTERN.
PATTERN can be a word, a list of words (separated by spaces),
or a regexp (using some regexp special characters). If it is a word,
search for matches for that word as a substring. If it is a list of words,
search for matches for any two (or more) of those words.

With C-u prefix, or if `apropos-do-all' is non-nil, also show
noninteractive functions.

If VAR-PREDICATE is non-nil, show only variables, and only those that
satisfy the predicate VAR-PREDICATE.

When called from a Lisp program, a string PATTERN is used as a regexp,
while a list of strings is used as a word list.