A more thorough explanation:

The Defense Information Systems Agency (DISA) is a government agency within the U.S. Department of Defense. Its main responsibility is to create and manage information systems that provide support to the military during combat.

For example, DISA might develop a system that allows soldiers to communicate with each other in real-time during a battle. This system could include secure messaging, video conferencing, and other features that help soldiers coordinate their actions and stay safe.

Another example of DISA's work might be the development of a system that tracks the location of military vehicles and personnel. This system could use GPS technology to provide commanders with real-time information about the movements of their troops, which could be critical in planning and executing military operations.

Overall, DISA plays a vital role in ensuring that the U.S. military has access to the information and technology it needs to succeed in combat.