A phone number is a unique series of digits assigned to a telephone or mobile device, allowing people to make and receive calls. Each number is usually made up of a country code, area code, and a local number, which helps identify the specific location or service provider. When you want to contact someone, you simply dial their phone number on your device. This connects you to their line, enabling communication. In today's world, phone numbers are also used for texting, online accounts, and even two-factor authentication, making them an essential part of modern life.