Different categories of UTP (Unshielded Twisted Pair) cabling were created for better performance in certain applications. As a general rule, the higher the category number, the higher the noise reduction and lower attenuation, and consequently the higher the bandwidth. For example, CAT6 can handle higher data rates at longer distances than CAT5 can. Newer categories have been added since the original revision to achieve these higher data rates.
The most widely used cable for Ethernet is CAT5e, which is good for most gigabit Ethernet applications. StarTech.com offers CAT5e, CAT6, and CAT6a Ethernet cables.
Any cable type can be used in any application as long as it meets the transfer speeds required for the application.
The following table compares the UTP cable categories:
| Category | Typical Application | Maximum frequency | Maximum length for application |
| CAT5 | 10/100 Mbps Ethernet | 100 Mhz |
100 meters for 100BASE-T |
| CAT5e |
10/100/Gigabit Ethernet |
100 MHz |
100 meters for 1000BASE-T |
| CAT6 | Gigabit Ethernet | 250 MHz |
100 meters for 1000BASE-T |
| CAT6a | 10-Gigabit Ethernet | 500 MHz |
100 meters for 10GBASE-T |
Note: The performance of any UTP cable is dependent on the length used and how the cable is terminated.