In simple terms, safety signs are signs that include a range of messages with the intent of keeping people from physical harm. Other signs are preventive in nature, instructing people for or against taking certain actions. A third type of safety signs are those categorized as informational and simply alert people to certain information, such as the whereabouts of a fire extinguisher. These signs are found in a range of different locations: factories, offices, educational institutions, and just about in any place where large amounts of people congregate.