Core Circuit Training focuses on the various muscles of the abdominal and spine, the movements are designed around rotation and lateral exercises. The circuit will also contain some isometric and mobility plank exercises to help with stability.
Depending on the ability and level of fitness, you can progress most of the core exercises by introducing the Swiss Ball, Medicine Ball or using a Wobble Board. The idea behind using these pieces of equipment is to de-stabilise, this makes your core muscles work on keeping your balance as well as doing the main exercise.
For Example, you would probably see the following exercises done in a Core Circuit Workout:
All three of these can be made harder by using the Swiss Ball, when you start to find an exercise easy start looking for a way of making it harder.
Usually a shorter circuit that has been designed to focus on the abdominal and spine areas.