There are two basic types of Ethernet cable connections: straight-through and cross-over. Straight-through A straight-through cable is wired the same on both ends. It’s mainly used when you’re connecting different devices, like a computer to a switch, or a router to a switch. Cross-over A cross-over cable is wired differently on each end so the send and receive lines are swapped. It’s mainly used when connecting similar devices directly, like a computer to another computer, or a switch to another switch. Why it matters Knowing the difference helps you avoid connection issues and understand how devices talk to each other on a network. Even though modern devices can often figure it out automatically, it’s still a core networking concept you’re expected to know.