Day trading is when opening and closing positions within the same trading day. This is the best way to avoid overnight risks which cause price gaps at the next day opening, but it also reduces the potential for big profits from these gaps. On the other hand, swing trading is when we keep the position open overnight. The duration might be from two days to three months (there is no exact definition). Someone can get in at 15.59 today and get out at 09.31 tomorrow and this is also a swing trade. Both terms denote short term trading.
The bigger the time horizon of the trade the more profits we expect to earn and the bigger the stop loss orders will be. In day trading the goal is to capture a price move of 10, 20, 50 cents (depends on the strategy and the stock price), but in swing trading, depending on time horizon, we expect much more. In day trading the basic charts are small time frames (less than 1 day), without excluding the daily chart for definition of main areas of support and resistance, whereas in swing trading the basic time frame is the daily, without excluding smaller time frames for better timing.