There are a few steps to setting this up, but it's worth it. Once you have Homebrew, installing other stuff is much easier.
You'll need to have a recent XCode on your machine for Homebrew to work.
Also, take ownership of the
/usr/local directory (inside which Homebrew needs full access) with this command:
$ sudo chown -R $(whoami) /usr/local
brew doctorto diagnose any potential problems with how your system is set up. Try to follow its instructions to fix any problems. (Ask for help if needed.)
brew is generally used for installing command line tools and other technical things,
brew cask is for installing regular Mac apps like Firefox and Slack.
To activate Cask:
$ brew tap caskroom/cask
It allows you to install lots of Mac apps from the command line, like this:
$ brew cask install firefox
More information: caskroom.io
The main things to know:
it's a good idea to run
brew update before running
brew install XXXXX. This downloads any recent formula changes from Homebrew (and these changes are happening all the time).
brew doctor can help diagnose issues with your system.
The Homebrew repo has lots more documentation.