Plugs are devices used to connect electrical appliances to a power source. They typically consist of a plastic or rubber casing with metal prongs that fit into an electrical outlet. Plugs come in various shapes and sizes, depending on the country and the type of appliance they are designed for. In addition to electrical plugs, the term "plug" can also refer to items used in other contexts, such as earplugs that block out noise or plugs in plumbing that seal openings. Each type of plug serves a specific purpose, making them essential in everyday life.