Cortana, the personal assistant technology was first demonstrated at the Microsoft BUILD Developer Conference in 2013. Voice activation is a feature that enables users to invoke a speech recognition engine from various device power states by saying a specific phrase - "Hey Cortana". The "Hey Cortana" Voice Activation (VA) feature allows users to quickly engage an experience (e.g., Cortana) outside of their active context (i.e., what is currently on screen) by using their voice. The feature is targeted for scenarios when the screen is off, idle or when it is fully active. If the hardware supports buffering, users can then chain the key phrase and command phrase together. This improves the end to end wake on voice experience for the user. For more information, see Voice Activation.