brew is a package manager for MacOS. It allows you to easily install, update, and manage software on your Mac. brew uses a command-line interface, which means that you can use it from the terminal window. With brew, you can install many useful command-line tools and utilities that are not included by default in MacOS. For example, you can use brew to install the wget utility, which allows you to download files from the internet, or the git version control system, which is widely used in software development. brew is a popular choice for managing software on a Mac because it is easy to use and has a large community of users who contribute to the project.

To install brew on a Mac, follow these steps:

1. Open a terminal window by pressing Command + Space to open Spotlight search, typing terminal, and pressing Enter.

2. In the terminal window, type /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" and press Enter to run the brew installation script.

3. You will be asked to enter your password to allow the installation to proceed. Type your password and press Enter.

4. Once the installation is complete, you can type brew doctor to verify that brew is installed correctly and that your system is ready to use it.

5. You can now use brew to install and manage software on your Mac. For example, to install the wget command-line utility, you can type brew install wget at the terminal prompt.