I'm new. What are the small contacts on the ends of the track. What are they for?
See pic
Are you talking about the metal rail joiners that keep the power flowing from one piece to another?
Or are you talking about track like this that has vertical metal pieces on the nubs? The track in the picture is for the auto reversing set up.
(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTUrl-_ujlLKVU6DZ2faT1AQW9YVqUHVx19cA&usqp=CAU)