The military needs to use servers in modern vehicles because technology has increased to the point where many things are impossible without computers. There is simply no way information is going to get from one point to another fast enough without using computer technology. There are also a lot of pieces of technology out in the field that need to have computers to interface with if they are going to be of any use to the troops while they are fighting. It is important that these things work at all times so that soldiers are safe and have every possible advantage over their opponents.
The difference between a traditional system and a rugged server is that the rugged version is designed to be strong and durable. A war zone is not a quiet place and it can be very hard on the team. If the vehicle catches fire, the computer could be exposed to shrapnel, smoke, and other similar problems. Even if it doesn’t take fire, weather conditions or fast movement over rough terrain could be really tough on a computer. A strong casing is needed so that the delicate electronic components are not damaged.
For example, robust systems with video surveillance equipment could be used. This could be mounted on a vehicle so it can be used in the field. The system would be used to record all actions that were observed by the camera. These tapes could be examined by officers at a later date so they could determine what to do next if enemy movements were caught on camera. These tapes could also be used after a battle to see what happened, to study the conflict.
A resilient server could be used to transmit the data from the camera to the main base. Patrols often wander so far from base that they can’t return every night. They have to stay alone. If the vehicles are damaged, they could be alone for days or weeks. The data still needs to be transmitted to the base to be analyzed.
In general, robust systems are used so that troops can have the best technology in the world regardless of their location. These are made to withstand life in a war zone. Many weapon systems are linked to computers, and communications systems use them almost exclusively. Servers can be used in any of these capacities, and some are used in multiple ways at the same time.