The International Mobile Equipment Identity (IMEI) number is a unique identifier assigned to every mobile device with cellular capabilities. It serves as a sort of "fingerprint" for the device, allowing it to be tracked, identified, and authenticated by mobile networks and various regulatory bodies. Here's a description of IMEI numbers and their significance:

An IMEI number is a 15-digit code that comprises several sections with specific meanings:

• Type Allocation Code (TAC): The first 6 digits of the IMEI represent the TAC, which indicates the manufacturer and model of the device.
• Serial Number: The following 6 digits represent the serial number of the device.
• Check Digit: The last digit is a check digit calculated using the Luhn algorithm. It's used to verify the accuracy of the IMEI.