What defines an in-line device within electrical systems?

An in-line device is defined by its position in an electrical circuit, specifically that current flows through it as part of its operation within the electrical system. This means that for any electrical signal or current to pass from one part of the system to another, it must travel through the in-line device, making it integral to the functioning of the circuit.

In contrast, devices that store energy for later use are typically considered energy-storing components, not in-line devices. Those that operate only during peak load refer to load management strategies rather than the continuous flow of current. Lastly, devices that reduce overall system voltage usually serve specific functions like transformers or voltage regulators, and do so by manipulation of voltage rather than by requiring current to simply flow through them. Thus, the defining characteristic of an in-line device in electrical systems remains its role as a component through which current continuously passes.