A Watch means conditions are favorable for severe weather to develop. They are usually issued several hours in advance of the storms.
A Warning means it's happening now and you should seek shelter now!
Orange shaded boxes within a county thats a Severe Thunderstorm Warning.
Sometimes there will be advisories, watches, or warnings stated in the legend but not colored on the map. The reason is in order to get the information for eastern Oregon we have to put up with any alerts in western Oregon too.