GitHub is where most of the world’s code lives: repositories with the pull-request review flow every developer knows, Actions for CI and automation, Issues and Projects for lightweight tracking, and Copilot woven through the editor and review. The free tier covers private repos for small teams.
It suits essentially any team writing software — the network effect is the product. Teams wanting one self-hostable platform for the whole DevOps lifecycle are GitLab’s audience; deeper project management usually pairs GitHub with Linear or Jira.