Sometimes abbreviated as Serial No., SN or S/N, a serial number is a unique number used for identification and inventory purposes. A serial number allows a company to identify a product and get additional information about it, for replacement, or as a means of finding compatible parts. Below is an example of what a serial number may look like on the back of a computer.
Locating serial numbers
Hardware - A serial number for a hardware device such as a computer or printer can almost always be found on the bottom or back of the device.
Software - Software serial numbers, also known as product identification numbers and CD-KEYs, are included with the packaging that the software was included in or on the case the CD is stored in.
Also see: Model number