What are the signs and symbols used in communication?

If you look around you, you will see signs and symbols everywhere. These signs and symbols tell you something, but you must know certain facts before you can understand them. Since they tell you something without actually speaking, we call them visual communication. Or, they are messages without words.   Traffic lights, flags, dots and dashes, pictures of men, women or children, rockets and flares are all forms of visual communication. Everyday signs that we see can be as simple as an arrow showing direction, or as complex as a mathematical symbol. Colours are also an important form of visual communication. Everywhere in the world, a red light means ‘stop’ and a green light means ‘go’.  Deaf people ‘speak’ through signs, and blind people can read using a system known as Braille in which they run their fingertips over raised bumps that represent words. Even Nature has its own warning signs. A wasp’s yellow and black stripes warn other animals that they sting. The colour or some lizards also acts as a warning that they taste horrible