Day Trading is a speculative trading style that involves the opening and closing of a position within the same day.
Quick example: If you open a new position at 10AM and close it by 2PM on the same day, you have completed a day trade. If you were to close that same position the following morning, it would no longer be considered a day trade.
Day traders, or active traders, typically use technical analysis and a trading strategy to try and make profits in a short period of time and will often use margin to increase buying power.
A successful day trader doesn’t just pick any stock and try to trade it. There has to be some kind of strategy involved with rules and money management parameters.