The different types of Ethernet cables are identified by category with the main ones being CAT3, CAT5, CAT5E, and CAT6. The styles are based on the type of application needed and range from small, lower quality to extremely sensitive high quality.
The standards are called 10BASE-T or 100BASE-TX, which is how cabling is categorized. 10BASE-T means 10 Mbps baseband can travel up to 185 meters. Mbps refers to the number of megabits per second data is transmitted. BASE means baseband, which is the signal and systems frequencies travel across when delivering transmissions. 100BASE-TX is a much faster Ethernet and runs on only two pairs of wire.
CAT3 is an older generation Ethernet cable and is mostly used in Voice over Internet Protocol (VoIP) due to the slow transmission speed. Originally used for computer networks, the CAT3 cable is only used in telephone installations. The transmission speed is relatively slow at ten megabits per second and the maximum frequency is only 16 MHz, which makes it too slow for today's computer networking requirements.
A crossover Ethernet cable connects devices together directly instead of through a router. The reason this type of Ethernet cable is called a crossover is because the connections inside the cable cross over each other instead of requiring a switch. These types are twisted with insulated copper wires and link to the Internet with four pairs of wire using category 5, or CAT5E, cabling.
The CAT5 Ethernet cable can perform at frequencies up to 100 MHz, which makes it suitable for today's network environment. Known as fast Ethernet, CAT5 is the most common type of Ethernet cable used since the mid-2000s. A more recent improvement is the CAT5e that supports both fast Ethernet and gigabit Ethernet. Other enhancements the CAT5e has over the CAT5 Ethernet cable is less cross talk and the ability to be backward compatible.
CAT6 has even more enhancements to a CAT5. Able to operate at frequencies up to 250 MHz, a CAT6 Ethernet cable is made of four pairs of twisted wires. The wire is better insulated than earlier versions and that allows the cable to perform better. A downside is that the thicker wire makes it incompatible with some earlier applications, which is why, though better, is not as widely used as the CAT5 type.