When you buy a cryptocurrency and sell it on the same day, this trade is known as an intraday trade. The process of buying and selling on the same day is known as intraday trading. Someone who does intrade trades frequently is known as intraday trader or day trader.
To know about intraday fees, please check this link.
Note: For the purpose of intraday rebates, “same day” is the period from midnight-of-a-day to midnight-of-the-following-day.