1. The document discusses various physical media used for networking including copper cables like coaxial cable and twisted pair, optical fiber, and wireless technologies.
2. It describes the characteristics of different cable types like bandwidth and attenuation. Category 3, 5, 5e, and 6 unshielded twisted pair cables are commonly used for Ethernet networks.
3. Optical fiber uses the principle of total internal reflection to transmit modulated light for communication. Multimode fiber supports less bandwidth than singlemode fiber.