What Is a Serial Number and What Is It For?

Definition of Serial Number & Why Hardware and Software Often Uses Them

An illustration of a Samsung serial number
Serial Number Location on a Samsung Notebook. © Samsung

A serial number is a unique, identifying number or group of numbers and letters assigned to an individual piece of hardware or software.

The term serial number is often shortened to justĀ S/N or SN, especially when the word precedes an actual serial number on something.

Serial numbers are sometimes, but not often, referred to as serial codes.

Hardware Serial Numbers

You've probably seen serial numbers many times before.

Nearly every piece of the computer has a serial number including your monitor, keyboard, mouse and sometimes even your entire computer system as a whole.

Internal computer components, like hard drives, optical drives and motherboards, also contain serial numbers.

Serial numbers are used by hardware manufacturers to track individual items, usually for quality control.

For example, if a piece of hardware is recalled for some reason, customers are usually made aware of which particular devices need service by being provided a range of serial numbers.

Software Serial Numbers

Serial numbers for software programs are typically used to help ensure that the program's installation is only performed one time and only on the purchaser's computer. If you're planning on reinstalling a software program you've purchased, you'll sometimes need the serial number to do so.

Below are some of the more common questions I get about software serial numbers:

A serial number for a piece of software is not usually the same as a product key but they are sometimes used interchangeably.

UPC Codes are different than serial numbers because UPC Codes are not unique to each individual piece of hardware or software, as serial numbers are.