Checking out a commit directly detaches HEAD from a branch name. You can inspect or even commit there, but new work needs a branch name if you want an easy route back to it. Read the current state before switching away. These tasks ask you to inspect an older snapshot explicitly and keep its file content visible. A normal switch to main selects a branch tip instead and would not satisfy the requested historical view. A detached checkout changes the visible tree without moving main. Creating a branch there would preserve any new work. These inspection tasks leave that choice for later and require the historical content itself.