Watches and warnings are usually denoted by color-coded shading along the coastline of the landmasses impacted by the storm. As a general rule of thumb, everyone in the Atlantic and eastern Pacific use the National Hurricane Center's yellow/blue/pink/red color coding. These watches and warnings often extend farther inland than just the coast.
A tropical storm/hurricane watch means that tropical storm/hurricane conditions are possible within the next 48 hours
A tropical storm/hurricane warning means that tropical storm/hurricane conditions are possible within the next 36 hours.
The map above shows the watches and warnings in effect this afternoon for the Antilles in advance of Tropical Storm Bertha.