Git is a distributed version control system used to track changes in source code during software development. It allows multiple developers to collaborate on projects by managing different versions of files, enabling them to merge changes, revert to previous states, and branch off for new features. Git stores the complete history of a project locally, making it fast and efficient. It is widely used in software development and integrated into platforms like GitHub and GitLab, which provide additional tools for collaboration, issue tracking, and code sharing. Git ensures better code management and facilitates teamwork.