Quantization: The process of converting a continuous range of values into a finite range of discreet values. Used for various applications in digital image and audio production. More info: Quantization
Qubit: Short for quantum digit or quantum bit, the basic unit of a quantum computer, equivalent to the binary bit in traditional computers. Can be state 1 or 0 (pronounced ket 1 and ket 0), or a quantum superposition of the two — this allows vastly more possible states than the binary bit.
Quicktime: A digital media format originally developed for the Apple Computer range, but is now also available for other platforms. More info: The Quicktime format