A serial number is a unique identifier assigned to an individual item, often used for tracking and inventory purposes. It helps manufacturers and retailers distinguish one product from another, even if they are of the same model. Serial numbers can be found on various items, including electronics, appliances, and vehicles, and are typically printed on labels or engraved on the product itself. These numbers are important for warranty claims, repairs, and recalls. For example, if a specific batch of electronics has a defect, the manufacturer can use serial numbers to identify affected items and notify customers. This ensures better customer service and product safety.