What does ‘Cat’ mean?
If you’ve ever browsed cables online, you’ve probably noticed that they’re nearly always classified as “Cat-5,” “Cat6e,” or something similar. “Cat” simply stands for “Category,” and the number that follows indicates the specifications to which the cable was manufactured. A general rule of thumb is that the higher numbers represent faster speeds and higher frequencies, measured in Mhz. As is the case with most technologies, newer cables tend to support higher bandwidths, and therefore increased download speeds and faster connections.
Keep in mind that longer Ethernet cables will result in slower transmission speeds, though cables bought for personal use rarely exceed 100 meters; and so are unlikely to experience much speed drop-off.
Below, you can see what each cable type is capable of.
Category Shielding Max Transmission Speed (at 100 meters) Max Bandwidth Cat 3 Unshielded 10 Mbps 16 MHz Cat 5 Unshielded 10/100 Mbps 100 MHz Cat 5e Unshielded 1,000 Mbps / 1 Gbps 100 MHz Cat 6 Shielded or Unshielded 1,000 Mbps / 1 Gbps 250 MHz Cat 6a Shielded 10,000 Mbps / 10 Gbps 500 MHz Cat 7 Shielded 10,000 Mbps / 10 Gbps 600 MHz Cat 7a Shielded 10,000 Mbps/10 Gbps 1,000Mhz
Cat 3 and Cat 5
Both Cat 3 and Cat 5 Ethernet cables are, at this point, obsolete. It’s not unheard of to find Cat 5 cables still in use, but you shouldn’t even think about trying to buy either of these Ethernet cables. They’re slow, and nobody makes them anymore.
The “e” in Cat 5e stands for “enhanced.” There are no physical differences between Cat 5 and Cat 5e cables, but 5e Ethernet is built under more stringent testing standards to eliminate crosstalk — i.e., the unwanted transfer of signals between communication channels. Cat 5e is currently the most common type of Ethernet cable, mainly due to its low production cost and ability to support faster speeds than the original Cat 5 cables.
Cat 6 cables support much higher bandwidths than Cat 5 and Cat 5e cables, but they’re also more expensive. Cat 6 cables are more tightly wound than their predecessors, and are often outfitted with foil or braided shielding. This shielding protects the twisted pairs of wires inside the Ethernet cable, helping to prevent crosstalk and noise interference. Cat 6 cables can technically support speeds up to 10 Gbps, but can only do so for up to 55 meters.
The “a” in Cat 6a stands for “augmented.” In comparison to the regular Cat 6 cables, 6a cables support twice the maximum bandwidth, and are capable of maintaining higher transmission speeds over longer cable lengths. Cat 6a cables are always shielded, and their sheathing — which is thick enough to eliminate crosstalk completely — makes for a much denser, less flexible cable than Cat 6.
Cat 7 cables utilize the newest widely available Ethernet technology, and support higher bandwidths and significantly faster transmission speeds than Cat 6 cables. They’re proportionally more expensive than other Ethernet cables, though their performance reflects their premium price tag. Cat 7 cables are capable of reaching up to 100 Gbps at a range of 15 meters, making them an excellent choice for connecting modems or routers directly to your devices. Cat 7 cables are always shielded, and use a modified GigaGate45 connector, which is backward compatible with regular Ethernet ports.
Although not widely available and with few supporting networking hardware options, Cat 7a currently offers the highest-specification Ethernet cables you can buy. Although the transmission speed is no different than that of Cat 7, Cat 7a cables offer a more than 50 percent improvement in overall bandwidth, which in certain settings may be useful. They are far more expensive than any other options though, and so they should only really be considered in very niche cases.
Cat 8 cables aren’t yet widely available but may become so in 2019. We can expect them to hit the market with faster maximum speeds and higher maximum bandwidths than Cat 7a cables.
The differences between the various types of Ethernet cables are actually pretty simple, but it’s easy to get confused by some of the nomenclature. To help out, we’ve put together a quick rundown on what different terms mean, and what you should expect if you buy a cable with those designations.
Cat: Stands for “category.”
TP: Twisted Pairs. This terminology refers to the way that the wires inside the cable are twisted together. Twisted Pairs have been an industry standard for years, and are only inferior to fiber-optic cabling in terms of maximum length and speed drop-off.
UTP: Unshielded Twisted Pairs. Cables designated UTP won’t have foil or braided shielding, which makes the cable cheaper to produce and more flexible, but you’ll sacrifice signal quality and increase vulnerability for crosstalk.
STP: Shielded Twisted Pairs. Cables with STP or SSTP designations are protected with braided shielding, which is usually made of copper or another conductive polymer. Shielding reduces noise and improves connection quality.
FTP: Foiled Twisted Pairs. Cables with FTPor SFTP designations are protected with foil shielding, which helps reduce noise and improves connection quality.
source : https://www.digitaltrends.com/computing/different-types-of-ethernet-cables-explained