The sprint is a new standalone race, on it some weekends this year. Qualifying for the race was yesterday, everything today is sprint. The shootout is open to everyone, it's qualifying for the sprint race later, which is 20 laps or 60 mins. Top eight I think? get extra points
It's a shorter qualifying session for the sprint race later today. I think that's the main difference, there's also suppose to be some tire restrictions but they ditched that today because of the wet conditions.