When you buy and sell a stock within the same day, it is called Intraday Trading. When you purchase shares and hold them overnight, then you take delivery of the shares and hence, this is called Delivery Trading. This is the difference between them.
Generally speaking, most brokers charge higher brokerage on Delivery trades versus Intraday trades.
Another benefit of Intraday Trading is that you receive margin benefits on Intraday Trading, while on Delivery based trades you have to pay the full value of the shares and the shares get credited to your account.