An extension is a number used within a private telephone network, such as a business or organization, to reach a specific person or department. It is typically used in conjunction with a main phone number, and the two are separated by a comma. For example, the main phone number for a company might be 555-1212, and the extension for the sales department might be 1234. To reach the sales department, you would dial 555-1212,1234.
Extensions are often used to direct calls to specific departments or individuals within a company. This can help to improve efficiency and customer service, as callers can be directed to the person or department that can best assist them. Extensions can also be used to provide additional information to callers, such as the person’s name or title.