When mechanics refer to toe-in or toe-out they are talking about the alignment for your front tires.Both tires should be parallel to one another but sometimes after hitting a pot hole or curb stuff can move. If the front of your tires are pointing towards each other (the center of the car) then that is refered to as toe-in. If they are pointed away from one another, then it is refered to as toe-out. If your tires are toed-in then the vehicle is very hard to keep going in a straight line and the outside edges of the tires will become very worn before the rest of the tire. If the tires are toed-out then the vehicle will loose power and the inside edges of the tires will become very worn before the rest of the tire. The only fix is to have the front end aligned on the vehicle and possibly will have to replace things that may have been bent or worn to cause the problem.