How can I determine which packages I have installed via homebrew and which were installed manually?

Question

I have a number of packages installed on my mac. Is there a terminal command that will allow me to determine which packages were installed via Homebrew?

For instance, I have R and git on my mac, but I know that neither R nor git were installed via Homebrew. Is there any other way to figure out which other packages were / weren't installed via Homebrew?

Answer 1

If you only want what you actually installed, and not also the (possibly hundreds of) dependencies that came with it: brew leaves.

That list is much nicer for re-installing things.