Explain Git rebase vs merge with trade-offs and when to use each.

Merge preserves history with a merge commit; rebase rewrites history to create a linear timeline.

Merge creates a new commit with two parents, preserving exact branch topology—safer for shared branches. Rebase replays commits onto a new base, producing a linear history that’s easier to read but rewrites hashes (dangerous on shared branches). Use rebase for local cleanup and feature branches; use merge for integrating into main or when preserving context is important.