When you move this something magical happens.
This....A light goes on outside your car and lets people know which way you are going to turn!!
Crazy I know, but it is proper road etiquette to use this magical lever.
You need to use this not only on the road but in parking lots as well. It can be a bit tricky though because sometimes when you use it you can forget to turn it off and that is just as bad as not using it at all.
Try to remember use it but don't abuse it.