What does this warning light on the dashboard mean?

Well, it could be alot of things. Oil may need to be changed, or pressure adjusted. A spark plug may need to be changed or the engine may be overheating. My advice is to take it do a mechanic to get it checked out in case it is very dangerous. Yellow or red? Yellow is just a caution indicator, check something that is getting low. Red is a warning indicator that something is WAY too low and may cause severe damage if you go on. want to know what a symbol means