What a dedicated circuit is
A dedicated circuit serves a single piece of equipment or a single outlet, with its own breaker at the panel. Nothing else shares the load.
Why equipment needs one
Appliances, HVAC equipment and some shop or medical equipment draw enough current — often continuously — that sharing a circuit would cause nuisance tripping or unsafe loading.
What installation involves
Installation generally means confirming panel capacity, adding a correctly sized breaker, routing new wiring to the equipment location, installing the outlet or connection, and testing the circuit.