Digital Data - Chapter 1

Question 1

What is a pixel ?

Answer 1

The smallest unit of a digital image that can be displayed and edited on a computer screen.

Question 2

What are bitmap graphics ?

Answer 2

• Store details about every individual element or pixel that makes up an image
• storing every pixel means that the file size can be very large.
• a bitmap image can also be compressed, which reduces the file size.

Question 3

What are vector based graphics ?

Answer 3

• vector based graphics store information about the components that make up an image; these components are based on mathematical objects such as lines curves and shapes.

Question 4

What is streaming ?

Answer 4

Streaming is a process that allows video to be viewed on a website straight away, without having to wait for the full video to be downloaded.

Question 5

What is buffering

Answer 5

A buffer is computer memory used
To store a part of the video downloaded before it is watched

Question 6

What is image resolution ?

Answer 6

The image resolution tells us the quality of an image, the more pixels the higher the quality and sharpness of the picture

Question 7

What is data ?

Answer 7

Data is raw, unorganised facts that need to be processed. Data has no meaning.

Question 8

What is information ?

Answer 8

Information is when data is processed, organised, structured, or presented in a given context so as to make it useful/ meaningful.

Question 9

What is the sample rate ?

Answer 9

Sample rate is how many samples, or measurements, of an audio recording or sound per second. The more samples per second are taken, the more detail in the sound waves (higher quality)

Question 10

What is the bit rate ?

Answer 10

Bit Rate of a file or audio tells you how many bits can be processed per second. Bit rate is measured in kilobits per second (kbps)

Question 11

What is bit depth ?

Answer 11

Bit Depth is the number of bits available to store sound samples. High quality audio samples require high bit depth

Question 12

What is a ADC , analogue to digital converter.

Answer 12

ADC stands for Analogue to Digital Converter, which converts sound waves to digital waves that are easier for a computer to read. Frequency at which samples are measured is in Hertz (Hz

Question 13

What is lossy compression

Answer 13

Lossy compression reduces the file size by removing data such as taking the colours out of a photo

Question 14

What is lossless compression ?

Answer 14

Lossless compression reduces file size without effecting quality.

Question 15

What is data portability ?

Answer 15

The ability to transfer data from one computer to another without having to re-enter the data.

Question 16

What is data compression ?

Answer 16

Data compression is used to convert digital data to as small a size as possible while still maintaining the quality of the data contained in the file ; allows data to be sent over the internet with acceptable transmission speeds.