What is the primary difference between straight-through and crossover Ethernet cables?

The primary difference between straight-through and crossover Ethernet cables lies in their usage concerning the types of devices they connect. Straight-through cables are typically used to connect devices of the same type, such as a computer to a switch, or a switch to a router. This is because the wiring configuration in straight-through cables matches the pinouts of identical devices.

On the other hand, crossover cables are specifically designed to connect different types of devices, such as connecting a computer directly to another computer, or a switch to another switch. The wiring configuration in crossover cables allows for the correct signal transmission between these differing devices by crossing over the transmit and receive pairs.

This fundamental purpose of straight-through for similar devices and crossover for different devices clarifies the appropriate scenarios for each cable type. It is important to use the correct type of cable to ensure proper communication between networked devices.