dish network rg-59/u coaxial cable

So I have this cable and it works just like any AV cable but it is soooooo much thicker; I mean the size of it. It is like 3 times as thick as a normal AV cable. What is the difference between this cable and a normal AV cable? also, where can I buy this cable (dish network rg-59/u coaxial cable) ????