Git is a distributed version control system that aims to provide speed, a simple design, strong support for non-linear development with thousands of parallel branches, and efficiency for large projects. It allows nearly every operation to be performed locally, with key operations including cloning a local copy of a remote repository, adding and committing files with commit messages, and pushing changes to the remote repository. Best practices for Git include checking for new changes before development, committing small non-breaking changes often with meaningful messages, using meaningful branch names, and configuring lifecycle hooks.