# Introduction <div class="alert alert-warning" role="alert"> <p>🧑💻 New to Git or LabEx? We recommend starting with the <b><a style="color: unset;text-decoration: underline;" href="https://labex.io/courses/quick-start-with-git" target="_blank">Quick Start with Git</a></b> course.</p> </div> In Git, a repository is a collection of files and folders that are tracked by Git. When you make changes to your files, Git creates a new version of the file and stores it in the repository. Over time, your repository can become cluttered with old versions of files and other unnecessary data. This can slow down Git and make it harder to work with your repository. In this lab, you will learn how to optimize your local repository to improve its performance.
Click the virtual machine below to start practicing