Postal codes are a series of letters and/or numbers assigned to specific geographic areas to help with the sorting and delivery of mail. They make it easier for postal services, like the United States Postal Service or Royal Mail, to quickly identify where a letter or package should go. For example, in the United States, a postal code is known as a ZIP code, which usually consists of five digits. These codes can also be useful for other purposes, such as finding local businesses or determining sales tax rates. Many online services use postal codes to provide accurate information based on your location, making them an essential part of modern communication and commerce.