The difference between cyclones and hurricanes once was the point of origin for the storm and the wind speed. However, it appears now that even meteorologists use the words interchangeably – after all in essence they are similar things.
A tornado though is a much smaller storm but caused in a similar fashion. First you need a supercell, which is basically big storm, then again you have the effect of warm moist air low and cool dry air above. The warm air rushes up, pulling in more warm air. These take place over land and when over the ocean are referred to as water spouts, because it looks like water is being sucked into the sky.