Not silly....Aqua girl provided a good explanation. Each Cathe round is about 1 minute of each exercise in the round, so about 4 minutes/round. There's about 6-8 rounds per workout. They're a type of circuit workout. I think the Strong & Sweaty Bootcamp substitutes a compound exercise for the core one.
One of my favorites is ICE Bootcamp Circuit- it has some standing core work. I was too intimidated by Bootcamp workouts until I did this one. Now Bootcamps are one of my favorite type of formats. A little bit of everything!