Icons are simple pictures or symbols that represent something without using words, making them universally understandable. They are used to represent common actions, like play, record, and stop, or concepts like time, messages, and navigation directions. While some icons resemble the objects they depict, their specific meaning can depend on the context in which they are used, such as on a phone versus a shipping box. Overall, icons provide a visual way to convey important information to people regardless of language or reading ability.