2.1.4 Images, Sound and Instructions

Images:
(k) explain the representation of images as a series of pixels represented in binary
Images are composed of a series of pixels(smallest elements of an image) in binary

(l) explain the need for metadata to be included in a file such as height, width and colour depth.
Metadata-information about the image data that allows a computer to recreate the image from the binary data in a file, containing height, width(pixels) and colour depth(bpp).

(m) discuss the effect of colour depth and resolution on the size of an image file
The greater the resolution (number of pixels per unit), the greater the file size. The same applies for colour depth.


Sound:
(n) explain how sound can be sampled and stored in digital form
Sound is converted from analogue to digital by sampling the sound wave at set intervals and recording the values which are then saved and replayed by the computer.

(o) explain how sampling intervals and other considerations affect the size of a sound file and quality of it's playback
If the sample rate and bit rate (space available for each sample) are higher, the quality of sound will improve but the file size will increase.

Instructions:
(p) explain how instructions are coded as bit patterns 
Instructions in a computer are stored in binary, each represented by a bit pattern that the CPU recognizes as an instruction.

(q) explain how the computer distinguishes between instructions and data
When the CPU fetches data from memory it cannot tell the difference between instructions and data and it finds what it expects based on the program it is running.