At machine level, computers understand information only in terms of binary values: 1s or 0s, ON or OFF. Data or information has to be prepared in this way so that it can be described in this format; this process is called digitising. All sorts of information can be captured in binary values, including images, audio and sensory data. Images have to be converted to a grid of pixels (picture elements) with colour values for each one referenced by their location and specific amounts of red, green and blue (RGB). These values are held in the computer’s memory in a structure called an Array. Audio information can be digitised in a similar way, with analogue values of the frequency converted to 8-bit, 16-bit or 32-bit digital sound files. For both images and sounds, analogue to digital conversion is used to prepare material so that it can be further developed on a computer. The resulting images can then only be printed and sounds heard on a loudspeaker, if the information is converted back to an analogue format once again.