Git is an open source distributed version control system (VCS) developed by Linus Torvalds in 2005. Version control allows tracking changes to files over time through commits, enabling recall of specific versions. GitHub is a code hosting platform that allows collaboration on projects remotely using Git. Common Git commands include git init to create a repository, git add to stage files, git commit to save changes, and git push to sync a local repository with a remote one. Pull requests allow proposing and reviewing changes before merging into a main branch like master.