Yes, rum is made from molasses. They squeeze the juice from the sugar cane, then boil it until it becomes thick and dark. Then they mix it with water and ferment it.
Cachaça is make from the fresh squeezed sugar cane. Squeeze, ferment. I have some I picked up in Brazil that has an under taste of fresh sugar cane juice.
When you are in Rio, on the second main road from the beach, behind the the Palace Hotel is a shop that has around 100 different cachacas. And you can taste some.