A fleet sustains an organization; a task force sustains a mission

What distinguishes a fleet from a task force?

A fleet is organized to sustain itself as an enduring command, while a task force is assembled for a mission and still relies on other organizations for support.

Fleets and task forces can both contain unlike ship types, unlike the more homogeneous squadron or flotilla. The decisive distinction is support. A fleet is theoretically a self-sufficient organization with the structure needed to continue operating, while a task force remains dependent on a wider command for some of its needs. The British Battle Cruiser Fleet shows how formal naming can overstate independence because it still relied heavily on the Grand Fleet. Formations are better classified by command and sustainment than by size or the presence of a carrier.