noob question about trailing stops

When you post a trailing stop and the price moves and the stop tightens, does it stay that tight or does it stay put until the price moves to the original distance away?

For example, you buy at 1000 with a 50 pip trailing stop.

The price goes straight up to 1050 then down to 1025 and now the stop is at 1000.

When the price goes back up again, does the stop trail by 25 pips now? Or does it stay put until the price hits 1050 again?

Thank you.

If stop advances and never retreats.

If price is at 1,000 and the stop is a 50 trailing and price moves to 1,025, the stop is at 975.

If price falls back to 1,000, the stop is still at 975. If price then moves to 50, the stop will be at 1,000.

It always advances, never retreats.