Networking hardware: routers, managed vs unmanaged switches, access points, patch panels, firewalls, PoE injectors and switches, cable modems, DSL and ONT

A network is built from devices that each have one job. Knowing what each device does, and at which layer of the network it works, helps you design small networks, pick the right equipment for a customer, and track down faults. The A+ exam typically describes a need, such as powering a ceiling camera, connecting two subnets or tidying a wiring closet, and asks which device fits.