Every operations team has asked "what happens if we change this?" and then had to guess. Branches let you answer it with your real data.
An exact starting point
A branch pins the exact state of its parent when it is created. Reads on the branch see that state plus whatever you change there, and nothing else. Production keeps moving; the branch stays put until you decide otherwise.
Real logic, no real effects
Your operations, workflows and rules run on a branch exactly as they would in production. What does not happen is the outside world: a branch never sends an email, charges a card or writes to a connected system. External effects are recorded so you can inspect them, but they are never delivered.
Compare and decide
Open a branch next to its parent to see what changed: which objects, which values, which follow-on work would have been triggered. Keep the branch for later, share it with a colleague, or discard it.
Try it
Create a branch from the workspace menu, make a change, and open the comparison view.