A straight-through cable is a kind of twisted-pair cable which is commonly used in local area networks to connect a computer to a network router. It is sometimes called a patch-cable and is substitute of wireless connection where more than one computers access a routing device through a wireless signal.
One way to find the specific use of straight-through cable is to relate it to a somewhat different kind of cable which is crossover cable. In straight-through cable, the wired pins match, while in a crossover cable the pins are typically reversed. A crossover cable is often used to connect two of the same kinds of devices i.e. computer to computer, switch to switch while straight-through cable connects two different devices i.e. computer to switch or computer to hub etc.
Straight through cable designs use several of the same standards and conventions at industry level. For example, a CAT-5e or CAT-5 cable structure can be used for both purposes. Cables are also subject to various other technical standards that provide consistency for such types of hardware connectors. Normally, a straight through cable will terminate in a registered jack connector which looks a bit like the common jacks on old-style telephone cables. Specific models of RJ connectors are utilized for these cable designs. Most common example is RJ-45 Connector. Length of straight-through cable can be more than 100 meters but signal to noise ratio become significant that it distorts the signal. Normally a hub or repeater is connected at every 100m distance which boosts the signal for effective communication.
Figure below shows the internal configuration in straight-through cable: