1.3.1

Question 1

Compression

Answer 1

The process used to reduce the storage space that a file needs

Question 2

Lossy Compression

Answer 2

Reduces the file size by removing non-essential information

Pro : Lowers file size more than lossless
Con : Original file cannot be restored

Question 3

Lossless Compression

Answer 3

Reduces the size of a file without losing any information by recording patterns in data rather than the actual data

Pro : Compressed image comes out with exact accuracy and no data is lost
Con : Larger file size compared to if lossy compression had been used

Question 4

Run Length Encoding ( RLE )

Answer 4

Compresses by recording every pixel in a sequence , recording its value and the number of times it’s repeated

Question 5

Dictionary Based Encoding

Answer 5

The compression algorithm searches through the text to find suitable entries in its own dictionary and translates the message accordingly

Question 6

Encryption

Answer 6

Used to keep data secure when it is being transmitted

Question 7

Symmetric Encryption

Answer 7

Private key

It uses the same key to encrypt and decrypt meaning the key must also be transmitted along with the data

Question 8

Asymmetric Key

Answer 8

Private key and public key

A public key is made public so anyone wishing to send you data can use the public key to encrypt there data and the private key is only known by the one receiving the data so that they can decrypt the message

Question 9

Hashing

Answer 9

A one way encryption system which is particularly useful for storing pins and passcodes as the encrypted data cannot be decrypted without the hash function