bottle
pre-built keg poured into a rack of the Cellar instead of building from upstream sources
cask
package definition that distributes vendor provided binary apps, most commonly closed source applications for the desktop
Caskroom
directory containing one or more named casks, e.g./opt/homebrew/Caskroom
Cellar
directory containing one or more named kegs, e.g./opt/homebrew/Cellar
formula
package definition that builds from upstream sources, e.g. from a GitHub repository
keg
installation destination directory of a given formula version, e.g. /opt/homebrew/Cellar/wget/1.24.5
keg-only
formula that is not symlinked into Homebrew’s prefix by default
tap
directory (and usually Git repository) of formulae, casks and/or external commands