To flip is to turn or toss upside down, like flipping a mattress over. People flip out when excited, and a flip remark is disrespectful.
There are many types of flips and flipping. Gymnasts who turn themselves upside down are doing flips. Turning a pancake over is flipping it. Any quick, light motion can be described as a flip, like a quarterback flipping the ball to a receiver. When someone is extremely excited — and usually mad — they flip out. Also, flip comments are casual, quick, and disrespectful.