Establishing a forward base is a strategy that helps maintain control of a specific area of the map. The base can be used as a sniping spot, a safe area for a bed to be placed, and/or a chest storage area for swords and other equipment. Often times a forward base has an iron door with a pressure plate on the inside of the base, making it difficult for intruders to enter without a pickaxe. If a team setting up a forward base lacks an iron door and/or pressure plate they can make a one-way staircase instead. However, this will limit the visability of incoming attackers and will prevent members of your own team from re-entering the forward base in the event they need to bring something back or forgot an item.
Placing a forward bed is not without its risks. If the enemy team does manage to overrun the base, those that have slept in the bed will have to run back from spawn until the next night. It is critical that you set the forward base a fair distance between you and the enemy, but not so close to home it is redundant with the main bed.