type tells you about the type of command you are inspecting. Tested on MacOS in Zsh.
type wow
# -> wow not found
function wow() { echo wow }
wow
# -> hey
type wow
# -> wow is a shell function
type cat
# -> cat is /bin/cat
type type
# -> type is a shell builtin
Assuming I have a custom shell function in ~/.zshrc called blah
type blah
# -> blah is a shell function from ~/.zshrc
Assuming I have an alias g for git in ~/.zshrc
type g
# -> g is an alias for git
type git
# -> git is /usr/bin/git
In zsh, the docs are in man zshbuiltins. There you learn that type is an alias for whence -v and takes almost the same flags as whence, which can also be found in man zshbuiltins.