Why Twisted Cable are Twisted ?

Twisted Pair Cable was invented by Graham Bell. As From Name anyone can Easily Understood
This is a type of Cable Which is Twisted on other Cable. But the question is why they are Twisted.
The Reason behind twisting is Cancelling out ,Electromagnetic Interference from External Sources
and Electromagnetic radiation from UTP (unshielded twisted pair cable ) cable.

• UNSHIELDED TWISTED PAIR

UTP Cable are used for Networking  and Traditional Telephone. There are Seven type of UTP Cable,

UTP CATEGORY	DATA RATE  (mb/s)	MAX-      LENGTH	CABLE-TYPE	APPLICATION
CAT 1	1	100m	Twisted pair	old-Telephone
CAT	4	100m	Twisted pair	Token Ring
CAT 3	10	100m	Twisted pair	Token Ring,10-base-T
CAT 4	16	100m	Twisted pair	Token Ring
CAT 5	1Gb/s	100m	Twisted pair	Token Ring, Ethernet,FE
CAT 5e	10Gb/s	100m	Twisted pair	Ethernet,FE,GbE
CAT 6	10Gb/s	100m	Twisted pair	GbE, 10-    GE(55m)
CAT 6a	10Gb/s	100m	Twisted pair	GbE, 10-    GE(55m)
CAT 7	10Gb/s	100m	Twisted pair	GbE, 10-    GE(100m

            

 NOTE- CAT 5e is most popularly used cable in all categories.