What is the significance of a double bid in bridge and how does it impact the bidding strategy of the players?

In bridge, a double bid is a bid made by a player to increase the penalty points for the opponents if they fail to make their contract. It signifies a strong belief that the opponents will not make their bid. A double bid can impact the bidding strategy by forcing players to reassess their hands and potentially change their bidding plans to account for the increased risk of penalties.