data representation

Unit Sizes:

4 bits → nibble

2 nibbles → byte

1024 bytes → kilobyte

1024 kilobytes → megabyte

1024 megabytes → gigabyte

1024 gigabytes → terabyte

Overflow error: the number of bits you need exceed the number of bits you have

Character set: all the different characters a computer can represent.

The difference between ASCII and Unicode is that there are only English characters on ASCII, so there is no other foreign language characters like Unicode. ASCII encodes 128 characters.

pixel: a tiny square or dot that contains a single point of colour of a larger image

colour density: the number of bits per pixel; determines the number of colours available

resolution: the density of pixels in an image. resolution is calculated by multiplying the width X height of an image.

metadata: the data about the data and is required to encode or decode the bits of an image

3 examples of metadata:

• location

• file size

• people in the image

file size: height X width X colour depth