A twist is commonly used in the section of the routine known as the tumbling passes.
The first video shows a 1/2 twist. A 1/2 twist calls for you to turn your body around half of the way.
The second video shows a full twist. The body must turn all the way through the air.
Twists are also a tumble that follows a roundoff back hand spring.
1/2 twist
Full Twist