Valet is a Laravel development environment for Mac users that allows for quick setup of local WordPress environments without relying on Vagrant or Docker. To set up Valet, users need to install Homebrew and PHP7.2, then run the `valet` command to access the installation menu. Users can create a database using MySQL and then install WordPress, which can be accessed through a custom URL created by Valet. The process is designed to be efficient and repeatable, allowing users to quickly set up multiple local WordPress environments.