Both normally state what their purpose is, machine or hand. Hand quilting thread usually has a lite coating of some sort of wax, like bees wax, where as machine quilting thread dosen't or it will gump up your machine. Some machine thread is all cotton some isn't, same as hand quilting thread. You really should get a book on the basic's of quilting to understand about thread as well as have a handy referrence to refer to.