The purpose of cable shielding is to create a barrier in order to protect the cable from any external interferences like EMI or electrical interference, and to prevent the cable signals from interfering with the surrounding cables.
The use of shielded cables is becoming more common, even though they are not required in all environments. At start, shielded cables were only applied in the installations in spaces with high concentration of electrical equipment and projects with secure communications applications. ...

The Category 6a, or Cat6A plenum cable
is the latest iteration of Gigabit Ethernet cabling. The a stands for augmented and is a nod to Cat6a Plenum improved specifications compared with its predecessor, the Category 6, or Cat6 plenum.

The Cat6A doubles data transmission bandwidth, from 250 to 500 MHz; decreases the chance of crosstalk interference; and provides superior reliability and transmission speeds through greater lengths of cable. Unlike most Cat6 cables, Cat6a cables ...