2.6 Data representation

Question 1

What are the two types of compression?

Answer 1

1) . Lossy Compression

2) .Lossless Compression

Question 2

What are the lossy compression formats?

Answer 2

1) . JPEG
2) .MPEG
3) .MP3

Question 3

what are the lossless compression formats?

Answer 3

1) . PDF
2) .GIF

files you would no want to lose data form:
spreadsheets,emails, text files, financial records

Question 4

Why is compression needed?

Answer 4

1) . to make data transfer quicker
2) . making storage capacity of file lower
3) . to reduce number of bits in a file

4). it is useful because more data can be stored on a storage device

Question 5

What is lossy compression?

Answer 5

• data is removed/discarded/lost and can not be recovered
• greatly reduces file size
• reduces quality of image/ sound
• cannot be used on text and executable files

Question 6

What is lossless compression?

Answer 6

• no data is lost - just encoded differently
• can be turned back into original format
• can be used on all types of data
• usually less effective than lossy compression at reducing the file size
• mostly suitable for documents and executable files