The UTP cable consists of pairs of wires twisted together. This is one of the most basic methods used to help prevent electromagnetic interference.
FTP offers an additional layer of protection with shielding (also called screening) wrapped around the individual twisted wires. This protects against EMI/FRI and crosstalk.
This has an overall foil or braid screen covering the 4 pairs of unshielded twisted pairs.
A combination of the two above, with foil shielding around the individual twisted wires and an overall screen which can sometimes be a flexible braid.This provides the maximum level of protection from interference and is found in the highest performance cables.