A new tropical storm formed over the central subtropical Atlantic late Wednesday, generating swells affecting the coast of Bermuda.

Hurricane Helene, which is currently Category 1, formed from an area of low pressure in the Caribbean, having strengthened rapidly over the last few days. The hurricane is expected to be the "strongest hurricane to make landfall in the U.S. this season," possibly hitting Category 3 or 4 strength.

All this talk about Hurricane Helene can be confusing. What is the difference between a tropical storm and a hurricane? Here's what to know.