With the advent of an environment like UEFI, it would stand to reason that a common concept like a shell would arise. Conceptually, a shell is built "around" some aspect of a rather complex system and provides simplified abstractions for users to gain access to the underlying infrastructure. These users could be pieces of software (such as scripts and applications) or they could be humans interacting with the shell in an interactive manner. A platform running a BIOS that is UEFI compliant is what might be characterized as the "rather complex item" that a UEFI Shell is built around. This article talks about various concepts such as how the UEFI Shell is abstracting the underlying UEFI compatible BIOS infrastructure, how certain concepts such as localization are accomplished within the shell, and the various manners in which a user can interact with the shell.