Fundamentals of data representation

Question 1

What is a bit?

Answer 1

A Binary Digit. The smallest digit in the binary system. 0 or 1

Question 2

What is a nibble?

Answer 2

Four bits

Question 3

What is a byte?

Answer 3

Eight bits

Question 4

What is a kiloByte?

Answer 4

1000X bytes

Question 5

What is a megaByte?

Answer 5

1000X kiloBytes

Question 6

What is a gigaByte?

Answer 6

1000X megaBytes

Question 7

What is a TeraByte?

Answer 7

1000X gigaBytes

Question 8

What is a binary shift left?

Answer 8

Multiplies a binary number by 2 for each shift left

Question 9

What is a binary shift right?

Answer 9

Divides a binary number by 2 for each shift right

Question 10

What is ASCII?

Answer 10

A 7-bit set of codes that allows 128 different characters. That is enough for every upper-case letter,
lower-case letter, digit and punctuation mark on most keyboards

Question 11

What does Unicode use?

Answer 11

Between 8 and 32 bits per character, which can
contain many millions of characters. It is commonly used across the internet. The first 128 characters in UNICODE are the same as the 128 characters in ASCII

Question 12

What are the cons of unicode?

Answer 12

As it is larger than ASCII, it takes up more storage space and network bandwidth

Question 13

What is an analogue?

Answer 13

Sound waves that are continuous waves that must be converted for a
computer to process

Question 14

What is a sample?

Answer 14

A measurement taken from an analogue sound wave at a point in time

Question 15

What is sample rate?

Answer 15

The total number of samples taken in 1 second, measured in the unit of Hertz (Hz)

Question 16

What is sample resolution?

Answer 16

The number of bits used to represent the value of a sample

Question 17

What is a pixel?

Answer 17

Smallest, most addressable part of an image

Question 18

What is bitmap?

Answer 18

A two dimensional array of binary data representing the values of pixels in an image

Question 19

What is image resolution?

Answer 19

The total pixels in an image which is expressed as a calculation of the pixels in the format of width x height

Question 20

What is colour depth?

Answer 20

The number of bits used to store each pixel. The more bits used to represent each pixel, the greater the total colour combinations will exist for the image

Question 21

What is data compression?

Answer 21

The process of reducing the size of data so that
it takes up less storage space. Compression can use either lossless or lossy techniques

Question 22

What happens when using lossy compression?

Answer 22

We can often receive a very small version of the original, however we cannot get back to the original data exactly as some data is lost in the process

Question 23

What happens when using lossless compression?

Answer 23

We may receive a smaller piece of data than the original data, however we can always recover the original data – no data is lost

Question 24

What is run length encoding?

Answer 24

A lossless data compression algorithm that converts consecutive identical values into a code consisting of the character
and a number marking the length of the run of the character

Question 25

What is huffman encoding?

Answer 25

A lossless data compression algorithm which allows a computer to compress and decompress a string based
upon how often characters are used