digital data Flashcards
what is data and information?
data is raw facts and figures/meaningless/haven’t been processed
information has meaning added/has been processed
put these in correct order = smallest to largest
gigabyte, bit, byte, megabyte, nibble, terabyte, kilobyte
bit, nibble, byte, kilobyte, megabyte, gigabyte, terabyte
what’s the difference between integer and real numeric numbers?
integer is a whole number
real has a decimal place
what is date and time as a data type?
you can choose how to format the date/time
long, medium or short date/time
What’s a character
A letter, symbol or number
What’s a string
A ‘text’ or ‘alphanumeric’
eg. A name = Sue Black
What is a Boolean?
True/false
What is a pixel?
The smallest unit of an image
‘Picture’ and ‘element’
What is colour depth?
N-bits per pixel
eg. You can have 2n different colours! 22^ = 4
What is the resolution of an image?
what does it tell us?
The number of pixels per inch/cm
it tells us the quality of an image
What does a higher resolution lead too?
Higher overall image loading
Higher processing times
Higher overall image file transfer times
bitmap graphics (or raster graphics) have…
A grid of tiny pixels Can edit individual pixels High-quality images Image can blur if stretched Takes up loads of storage Takes a long time to load
vector graphics have…
Stores details about individual components
Made up of objects
Quality doesn’t depend on resolution
Can be resized without loss of quality
Lack of a need to store individual pixels
What’s the difference between streaming and buffering?
- Streaming allows a video to be viewed straight away without having to wait for the full video to be downloaded
- Buffering holds the downloaded segments that have not yet been played
What is Sample Rate
• The quantity of samples taken per second
Measured in Hertz (Hz)
• Sample Rate higher = better quality
• Sample rate lower = reduces quality
• requires more storage space and more CPU time/processing power
