A hitch is a type of knot that is being tied around an object. A true hitch does need the object to maintain its form. If you remove the object then the hitch then most of the times the hitches falls apart. For your convenience we have split them up in slide and grip hitches (friction hitches) that are being used for climbing and general hitches that are used to tie a rope to an object. Technically they are both hitches because you are tying a rope to an object but in use they are very different.