TOPIC: Identify Risks Input

what's the difference between project schedule and schedule baseline.it looks like they are being used interchangeably . an example in identify risk process , why the schedule baseline used as input instead of the project schedule ??/

The schedule baseline is the 'ORIGINAL' schedule created. It is still the schedule until something changes, then the 'Baseline' just becomes the refrence point prior to changes so you can see how far something has changed from your 'Original' schedule d plan.
Yes, they are interchangeable until it changes, then you may two of them, one original, and one working schedule.
The schedule baseline is a true reflection of the original plan ad is used as an input because of it, not as a result of changes that occur later. Identify risks is in planning, so you more than likely only have the original schedule baseline at that point.