Gulp is a command line task runner that automates repetitive development tasks like SCSS/SASS compilation and file minification, improving efficiency by avoiding intermediary files. The document outlines steps to install and set up Gulp, including creating a gulpfile.js to define tasks, and demonstrates how to implement basic tasks such as compiling SASS and watching file changes. It emphasizes the use of Gulp's methods like src, dest, pipe, and watch for process automation within front-end development.