FTP/STP: STP, Shielded Twisted Pair shielding network line; FTP, Foiled Twisted Pair, aluminum foil shielding network wire; 

The former is a broad name and the latter is a narrow term.In fact, the current blocking network line is the aluminum foil shielding network wire, so STP and FTP are actually the same. 

Compared to UTP, FTP/STP is just a layer of aluminum foil outside the core to reduce the attenuation of the signal. 

The market is less popular.SFTP: double shielded network wire.

The structure of this wire is based on the aluminum foil of FTP/STP, plus a layer of tin-plated copper braided mesh, the outside of which is PVC.Due to the extra layer of tin-plated copper wire mesh, the external magnetic field can be greatly reduced, and the signal interference can also reduce the attenuation of internal signals and increase the tension of cables. 

The disadvantage is that this wire  is very soft and expensive. The price of this wire is usually twice that of UTP. This wire is only used in special circumstances and seldom to use.

wendy