Chapter 14: Data Storage & Compression

Question 1

Need for data compression

Answer 1

• Less storage space required
• Faster upload/download speeds
• Less bandwidth used
• Faster streaming speeds of video/audio files

Question 2

Decimal prefix

Answer 2

Multiplies a unit by powers of 10

Question 3

Binary prefix

Answer 3

Multiplies a unit by powers of 2

Question 4

Bit

Answer 4

The smallest unit of data that a computer can process & store

Question 5

Compression

Answer 5

Changing the format of a data file so that the size of the file becomes smaller

Question 6

Lossless compression

Answer 6

A form of data compression that reduces file sizes without removing any of the original data, allowing files to be reconstructed without loss of information when decompressed

Question 7

Lossy examples

Answer 7

JPG, GIF, MP3, MP4

Question 8

Lossless examples

Answer 8

PNG, TIF, SVG, PDF

Question 9

Lossy compression features

Answer 9

• Removes data permanently
• Reconstructs image without missing data
• Used for images & sound files
• Much smaller file size but loss of quality

Question 10

Lossless compression features

Answer 10

• Used for text files

Question 11

Lossy compression sound

Answer 11

Discards/removes frequencies which the human ear cannot hear or distinguish between

Question 12

Lossy compression image

Answer 12

Groups similar colours together by giving them same colour values. Reduces colour depth of image

Question 13

Bitmap image

Answer 13

Graphic image made up of pixels

Question 14

Lossy compression

Answer 14

A form of data compression that reduces the size of a file by permanently removing some of the data so that the original file cannot be reconstructed when decompressed

Question 15

Bandwidth

Answer 15

The amount of data that can be carried on a network in a given period of time