Regular sockets are designed for use with a ratchet, which is a handheld tool powered only by your own exertions. Impact sockets, however, are designed for use on an impact wrench, which is a handheld power tool that accomplishes the same thing as a ratchet, only with much more torque.  While you generally can use an impact socket on a regular ratchet, you cannot use a regular socket on an impact wrench. Impact sockets are specifically designed to tolerate the stress of rapid, high impact without cracking or shattering. Your regular socket is unlikely to survive the stresses of an impact wrench, and you could potentially be injured should the socket break apart during use.