There are two ways an aircraft meets the Remote ID requirement, and which one you use depends on the aircraft itself. Most drones sold now are standard Remote ID aircraft under § 89.110 — the Remote ID is built in, and the identifying broadcast comes from equipment the manufacturer put in the airframe. For a drone that is not a standard Remote ID aircraft — typically an older model — § 89.115(a) offers a retrofit: a Remote ID broadcast module you add to the aircraft. Both satisfy the rule, but they are not interchangeable in what they let you do.

The difference that matters most in the field is a single operating condition. A standard Remote ID aircraft carries no extra restriction from § 89.110 on how far away you fly it, so it can be used in operations that go beyond visual line of sight where the rules otherwise permit. The broadcast-module path is narrower: § 89.115(a) requires that you be able to see the aircraft at all times throughout the operation. The module keeps an older drone legal, but it ties that drone to flight within your sight — a real limit if your work depends on flying beyond it.