A sign is an image implying a relationship between an object and itself. There are natural signs and conventional signs. An example of a natural sign is a thunder which may indicate a storm. A conventional sign is a red light, indicating a full stop.
Road signs or traffic signs are used to provide information to motorists and road users. They are placed at the side of the road. Standardised road signs using symbols are used to simplify and facilitate road signs all over the world. This is done to enhance traffic safety in different countries with different languages. Symbols or pictorial signs are used instead of words to convey the information. Road signs are grouped according to their category. They may be categorised as regulatory signs, warning signs, guide signs, emergency management signs, school signs, railroad signs, bicycle signs or temporary traffic control signs. There are standards to be followed with the categories, placement and graphics for road signs. Traffic signs nowadays use electronic displays to convey the information to road users. These displays are capable of changing the symbol or text as messages through remote manual inputting or even by automated traffic sensing.
Aside from traffic purposes, signs are also used in varied ways. Astrology uses signs. Sign language obviously uses signs for communication. Mathematics and computer data processing uses symbols to solve mathematical and logical problems. Even in the workplace, safety equipment carries signs or there may be a sign telling employees to wear their hard hats. Some indicate a machine is currently in use. Safety signs are used to warn people of possible hazard and thus protecting people’s health and safety.