1 Coppercore: At the heart of nearly all guitar cables is a core of copper wire. Copper conducts electricity extremely well, which makes it a nice, easy pathway for the low-voltage (0.1-1V) signal from your pickups to travel along on its way to the amp. There are many styles of core, ranging from solid to braided types, but the bottom line is that copper is the king of non-precious metals when it comes to conducting electricity efficiently. The copper core is wrapped in a layer of insulation.
2 Braided shielding: The insulation itself is wrapped in a conductive sleeve, typically made of braided copper, which is connected to earth. This forms a shield that protects the core from electromagnetic interference from nearby power lines, appliances and so on, which can add unwanted hum to your sound.
3 Foil shielding: Sometimes leads have an extra layer of aluminium foil shielding on top of the braided shielding to really put the thumbscrews on hum.
4 Outersleeve: The final layer of the cable is a durable rubber or cloth sleeve that protects the cable from wear and tear.
5 Jackplug: To enable you to plug your cable into guitar and amp, each end is attached to a 6.35mm (quarter-inch) jack plug. The copper core inside your cable is soldered to a terminal inside the jack plug, which connects to the jack’s tip, allowing the signal from your guitar to pass from the cable to the amp. This core should ideally be made of copper, but brass or even steel are used in many cheap jacks. The cable’s braided shielding is earthed by connecting to a separate sleeve terminal, which in turn is connected to the body of the jack plug.
6 Strain-relief collar: To prevent these delicate solder joints being stressed every time you yank on the cable, the body of the jack plug is usually anchored to the tough outer sleeve of the cable with a tight-fitting collar that takes the brunt of the shocks.