A cable consists of one, two or more wires which connects input and output devices to the system via ports and connectors.
Types
Twisted pair cable:
Consists of two copper wires insulated from each other by plastic.
Each wire has two or more copper wires stranded together.
This reduces sensitivity to EMI and tendency to radiate radio frequency noise.
Twisted pair cables are of two types - shielded and unshielded.
Shielded cable are enclosed in foil wrap and woven in copper shield.
Unshielded cables are not enclosed.
Commonly used in telephone network.
Are less expensive and easy to install.
Cat 5 Cable
Consists of four pairs shielded twisted color coded copper wire.
Green, blue, orange and brown are four pair colors.
Each pair has common color between them, where one wire in the pair is solid in color and other being a white color with a colored strip. E.g.: orange for solid color wire and white/orange for the striped wire.
Supports 100 MBPS speed with length limit of 100 meters.
Starting and ending points of the cable are joined by RJ-45 connector.
Most commonly used in computer networking and are low in cost.
Cat 5e is enhanced Cat 5 cable supporting 1000 MBPS speed with length limit of 350 meters
Co-axial cable:
Replaces multiple wire lines by solid copper core.
Inner (Central) conductor is solid copper wire or stranded wire.
Outer conductor forms a tube surrounding inner conductor called as shield, which is made-up of braided wires, metallic foils or both. This serves as a ground and protects inner conductor from EMI.
An Insulator layer separates the outer and inner conductor.
Jacket made-up of plastic protects cable from damage.
Widely used in connecting PCs.
Cost is high compare to twisted pair cable.
Fibre-optic cable:
Light waves can be efficiently conducted through transparent glass fiber known as fiber-optic cable.
Center conductor consists of fiber optic tube which is highly refined glass or plastic.
Fiber optic tube is half the diameter of human hair.
Fiber is coated with cladding to reflect signals back to avoid signal loss.
Plastic sheet (Jacket) protects from damage.
Transmits data using beams of light at light speed.
Extremely high bandwidth supporting data transfer speed in GBPS.