Suddenly feeling interested about these three try to find out what Google said. Surprisingly find out there are people have written in different answer forum that those three are the damn same thing , which even lay man like me doesn't agree. At least I know that these are not the damn same thing !!!
And Tornado basically happen inside the land and hurricane is a sea storm.
To know the things in more detail, these three links are helpful
http://en.wikipedia.org/wiki/Tornado
http://en.wikipedia.org/wiki/Hurricane
http://en.wikipedia.org/wiki/Cyclone
