A ball is said to be skidding if it doesn't roll down the lane but rather slides.
If the ball flips from one side to the other while heading toward the pins, the ball is flipping.
If the ball slides down the lane and rolls from one side to the other when done sliding, the ball is performing a skid/flip.
Ball As a Cause
The higher the radius of gyration (RG) of the ball, the more likely it will skid/flip, because it is a higher differential ball. When a ball uses less energy in the front of the lane and more power in the back end, you could cause skid/flip. If you drill the ball to cause flare, you can also cause skid/flip, although this is the least likely of the causes related to the ball.
Lane As a Cause
If you play on wet or very dry lane, you are more likely to have a skid/flip occur. If the lane conditions change from wet to dry or vice versa, it can also cause the ball to skid/flip.