1.1Version Control, Git, and GitHub

A Version Control System (VCS) records the history of changes to files so you can revert to previous states and track who changed what and when. Without version control, you end up with copies like report_final_v2_really_final.docx and lose track of how things changed. A VCS solves this and gives you a foundation to change, experiment, and collaborate with confidence.

■ What Git is Git is a leading distributed VCS. "Distributed" means each developer holds a complete copy of the history locally, so you can commit, view history, and create branches without a constant connection to a central server—making offline work and parallel development easy. Git is open source and usable from the command line, GitHub Desktop (GUI), and many editors.

■ Git and GitHub are different A common misconception is that Git and GitHub are the same. They are not. • Git = the tool (software) that performs version control, running locally or on a server. • GitHub = a service that hosts Git repositories in the cloud and adds collaboration features such as Pull Requests, Issues, code review, and GitHub Actions. Git works without GitHub, and alternatives to GitHub exist (GitLab, Bitbucket, etc.). Understanding this distinction is the starting point.

■ Accounts and Enterprise GitHub accounts come as personal accounts (for one person) and Organization accounts (which group members and repositories). For larger organizations, GitHub Enterprise groups multiple organizations for centralized management and offers governance features like SAML single sign-on (SSO), centralized billing, and policy management. Enterprise comes in two forms: Enterprise Cloud (hosted by GitHub) and Enterprise Server (installed on your own infrastructure).