Prepare Phase:?

Short answer: The coordinator (typically a transaction manager) sends a prepare request to all participant services (e.g., databases). Each participant service checks if it can commit the transaction (e.g., by ensuring its local transaction is successful) and responds with a vote (either commit or abort).

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.