There are many weather terms and definitions out there, and it can be quite confusing to keep them all straight. The NHC and Hurricanes: Science and Society define the following tropical weather terms:

Tropical cyclone

A low-pressure, warm-core system with an organized wind circulation that forms over tropical (and sometimes subtropical) waters. Classified based on sustained surface winds, types of tropical cyclones are: tropical disturbance, tropical depression, tropical storm or hurricane.

Tropical disturbance: Unorganized systems of thunderstorms with very little wind circulation. Typically originates in the tropics but occasionally forms in the subtropics.
Tropical depression: A tropical cyclone with maximum sustained surface winds of 38 mph or less. A tropical depression may form slowly from a tropical disturbance.
Tropical storm: A tropical cyclone with maximum sustained surface winds of 39 to 74 mph.
Hurricane: A tropical cyclone with sustained surface winds greater than 74 mph. Hurricanes are classified into the following five categories based on wind speed:
- Category 1: 74 to 95 mph
- Category 2: 96 to 110 mph
- Category 3: 111 to 129 mph
- Category 4: 130 to 156 mph
- Category 5: 157 mph or greater

Understanding the difference between a hurricane or tropical storm watch and warning is crucial. Now, you have the knowledge to be better prepared the next time you're facing inclement tropical weather.