A straight-through cable is used to connect a computer to a switch. This type of cable has the wires connected identically on both ends, allowing for devices of different types (like a computer and a switch) to communicate with each other. A crossover cable has pairs of wires that cross over, which would be used for directly connecting two similar devices such as two computers. A rollover cable, conversely, has its wires connected completely opposite from one end to another and is typically used for configuration tasks on a router or a switch via the console port. A Power over Ethernet (PoE) cable is simply a standard data cable (straight-through or crossover) that also carries electrical power along with data.