What feature makes shielded twisted pair (STP) cables different from unshielded twisted pair (UTP) cables?

Shielded twisted pair (STP) cables are distinct from unshielded twisted pair (UTP) cables primarily due to the inclusion of armor and shielding. The shielding in STP cables provides a layer of protection against electromagnetic interference (EMI) and radio frequency interference (RFI), which can be critical in environments with many electronic devices or in industrial settings. This shielding typically consists of a foil or braid that surrounds the pairs of wires, helping to maintain signal integrity by minimizing the amount of external noise that can be picked up by the cable.

The additional layer provided by the armor and shielding contributes to STP's ability to support higher data rates and longer distances without degradation compared to UTP cables. While UTP cables are less expensive and more flexible, they do not offer the same level of performance in environments where interference is a concern. The differences in shielding and armor are essential for understanding how to choose the appropriate type of cable for specific networking situations.