Structured cabling, also called voice and data communications cabling, is the connection infrastructure standardized by TIA / EIA and by IEEE for telephone systems or local area networks (LAN). These regulations are TIA / EIA 568 and IEEE 802.3. Today, category cabling is also part of the audiovisual world.
This type of cable is composed of 4 twisted pairs (shielded or not) with impedance of 100 Ω. The conductor section will depend on the category, but they range from 24-23 AWG. The greater the category, the greater the diameter.
The different categories are named with numbers as follows: CAT.5, CAT.5E, CAT.6, CAT.6A, CAT.7, CAT.8.
Physically categories can be distinguished by the diameter of the conductors and especially by the turning torque of the pairs. The higher the category the turn will be smaller.