NetBIOS - Definition from the Hotspot Shield Glossary
NetBIOS adds networking functionality to the standard BIOS used on windows-based devices. The term stands for Network Basics Input Output System and was developed by IBM in the 1980’s.
The standard BIOS gives an interface between the operating system and hardware, NetBIOS gives an interface for devices to connect to and be recognized on a network. NetBIOS is primarily an API (application program interface) that developers use to add networking functionality into software and programs. This standardized API has been adopted by many and has become the standard for the computing industry - It enables developers to quickly add networking into their programs instead of re-writing the whole code from scratch.