Chapter 1 - Data representation Flashcards
(28 cards)
What is analogue data?
A continuous stream of data that is processed by humans.
What is a logic gate?
A very small component in a computer system that controls the flow of electricity.
What is digital data?
Discrete data that only uses the values 0 and 1.
What is a register?
A small component in a computer system that is used to temporarily store data.
What are the benefits of using hexadecimal rather than binary for a programmer?
- Hexadecimal is a shorter way of representing binary, so it takes up less space on the screen/piece of paper
- Hexadecimal is easier for a programmer to read, write and understand
- Hexadecimal is easier to debug and locate errors in data
What is a MAC address?
A unique address that is given to a computer at the manufacturing stage that can be used to identify the computer.
What is a character set?
A set that contains all the characters that are in that character set and the binary value that is assigned to each character.
What is the difference between the ASCII and Unicode character sets?
ASCII represents characters using 8-bit binary numbers (up to 256 characters) while Unicode represents characters using 16-bit binary numbers (up to 65536 characters).
What is a pixel?
A very small dot of colour that is displayed with many others to create an image.
What is resolution?
The dimensions of an image.
What is metadata?
Additional data that is stored with an image that can provide information such as the resolution, time and date the image was taken.
What is colour depth?
The number of bits that are used to create each colour in an image.
What is sound sampling?
A little piece of sound that is recorded at regular time intervals.
What is the sample rate?
The number of samples recorded each second.
What unit are sample rates measured in?
Hertz.
How can we improve the accuracy of a recorded sound?
Increase the sample rate.
How is the storage space affected when sample rate is increased?
Storage space also increases.
What is the sample resolution?
The number of bits that are used to record each sound sample.
What are the different data measurement units?
Check book page 25 table.
What is compression?
A method that uses an algorithm to reduce the size of a file.
What are the benefits of compressing a file?
- Not as much storage space needed
- Less time taken to transmit the file from one device to another
- Quicker to upload and download the file
- Not as much bandwidth needed to transmit the file over the internet
What are the two types of compression?
- Lossy
- Lossless
What happens in lossy compression?
A compression algorithm finds unnecessary and redundant data in the file and permanently removes it.
When do we mainly use lossy compression?
- Image files
- Sound files
