A swing trade typically tries to ride the ebb and flow of the market price. Buying when the price starts rising and then selling before it starts going down.
The goal is to capture a part of a move in the prices and then be out of the market when that move has run its course. That makes it possible to capture more profit than just a simple day trade. But on the other hand also makes the trade vulnerable to over night risks such as price gaps. A shorter time frame than long term investing is limiting the risk of noise and other unexpected events associated with of long term investing.