What is the process of an artist collector bidding higher over an artwork to win out another bidder called?

The process of an artist collector bidding higher over an artwork to outbid another bidder is typically called an "auction." More specifically, if the bidding escalates as participants compete against each other, it can be referred to as a "bidding war." In this scenario, bidders raise their offers in an attempt to win the artwork, often driving the price higher than initially anticipated.