A look at guided (cables) and unguided (wireless) media.
Transmission media is the physical path between a transmitter and a receiver in a data communication system. It can be broadly classified into two categories: guided and unguided. Guided media, as the name suggests, provides a physical conduit from one device to another. The three main types are twisted-pair cable, coaxial cable, and fiber-optic cable. Twisted-pair cable consists of two insulated copper wires twisted together to reduce electromagnetic interference. It's the most common type of cabling used in LANs (e.g., Cat5e, Cat6). Coaxial cable has a central copper conductor surrounded by an insulating layer, a braided metal shield, and an outer jacket. It is more resistant to interference than twisted-pair and is commonly used for cable television and early Ethernet networks. Fiber-optic cable is the most advanced form of guided media. It transmits data as pulses of light through thin strands of glass or plastic fiber, offering incredibly high bandwidth, long-distance transmission, and immunity to electromagnetic interference. Unguided media, or wireless communication, transports electromagnetic waves without using a physical conductor. This includes radio waves, used for AM/FM radio, Wi-Fi, Bluetooth, and cellular networks. Microwaves are also used for point-to-point communication and satellite links. Infrared, used in TV remotes, is another form of unguided media for short-range communication. The choice of media depends on factors like cost, bandwidth requirements, distance, and environmental conditions.