C⁵I is a military acronym describing the core capabilities involved in:

• Detecting pertinent military or civil activity
• Analyzing the intent or impact of the activity upon friendly forces
• Disseminating the activity and analysis to friendly forces
• Providing engagement orders to friendly units to interact, neutralize, or destroy
• Engaging hostile forces with weapons
• Capture and analyze battle damage assessment information

The "C5" part of the term summarizes five words that begin with the letter "C" — "Command", "Control", "Communications", and "Computers", and "Combat systems". The "I" portion refers to "Intelligence".

Military theorists previously used similar terms

C4ISTAR

In military usage, a number of abbreviations in the format C followed by additional letters are used, based on expanded versions of the abbreviation C2 - command and control.C2I stands for command, control, and intelligence....

, which accounted for fewer factors.