A few additions:
An "e" stuck on the end of the category denotes "
enhanced", therefore category
5e cable is enhanced category 5 cable. This simply means that the
physical and
electrical characteristics surpass those of the numbered category. An "enhanced" category or a larger number improves
performance due to better handling of
crosstalk,
attenuation,
impedance, and more.
ANSI/
TIA/
EIA-568-A is the main standard for UTP. This standard specifies up to category 5e. Any company who claims its product is category 6
compliant is referring to a
draft of a standard - and possibly not even the draft of the ANSI standard.