The sweatsuit and tracksuit are not just similar but are the same thing. Both are long-sleeved and long bottoms that can be paired with any top/shirt for a perfect outfit. The only difference is the elastic around the ankles.
The sweatsuit have the elastic around the ankles because it is usually worn by students who use the elastic to gather the ankle of the sweatsuit up so that the feet can be free to move. A tracksuit get named as such because they were first worn by track athletes who needed something to train and compete in.
Although both a sweat suit and tracksuit serve the same purpose, which is to keep you warm, they are different articles of clothing. Yes, the tracksuit, which was created in the 1970s, was based on the sweat suit but was modified so it became a more stylish form of clothing. which was created in the late 1960s and modified in the 1970s to become the tracksuit.