The following is the Congressional Research Service In Focus report, Joint All Domain Command and Control (JADC2).
From the report
What Is JADC2?
Joint All Domain Command and Control (JADC2) is the Department of Defense’s (DOD’s) concept to connect sensors from all of the military services—Air Force, Army, Marine Corps, Navy, and Space Force—into a single network. Traditionally, each of the military services developed its own tactical network that was incompatible with those of other services...