Last names, also known as surnames, are family names passed down through generations. They help identify individuals within a family and often indicate lineage, occupation, or geographic origin. For example, the last name Smith may suggest an ancestor who worked as a blacksmith, while Johnson indicates "son of John." In many cultures, last names are placed after the first name, but this can vary. In some countries, such as Spain, individuals may have two last names, combining both parents' surnames. Understanding last names can provide insights into family history and cultural heritage.