It's a package manager.
The second header on the main page:
What Does Homebrew Do?
Homebrew installs the command-line tools and applications you need across macOS, Linux and WSL.
The second header on the main page:
What Does Homebrew Do?
Homebrew installs the command-line tools and applications you need across macOS, Linux and WSL.
Homebrew is the Mac equivalent of APT, Pacman, RPM, BSD ports, etc. It's a fairly traditional package manager for software that doesn't come with macOS. "brew install postgresql" installs Postgres into /opt/homebrew, for example.