"Price" settlement.
Stock index futures are delivered in cash. The so-called cash delivery means that there is no need to deliver a basket of stock index components, but the spot index on the maturity date or the next day is used as the final settlement price, and the position is closed through profit and loss settlement at the final settlement price.
The two are consistent in theory, because the delivery price of stock index futures is based on the arithmetic average of a period of time before the final closing, and the closing price is the price at the last moment, so it will be slightly different.