A straight-through cable is a type of UTP network cable. UTP cables have eight wires, with each pair being twisted together. At each end, the wires terminate at pins in an 8P8C connector.
In a straight-through UTP cable, the wires always line up at each end. That is, pin 1 at one end will always line up with pin 1 at the other end. Pin 2 connects to pin 2, and so on.
Traditionally, straight through cables were used to connect devices like workstations, printers, and routers, to a switch.
An alternative to a straight-through UTP cable is the crossover cable. This was traditionally used to connect one device directly to another.
These days, nearly all UTP cables are straight-through. Crossover cables are very rare, thanks to a technology called Auto-MDIX.