Unit 1 Digital Data Flashcards
What is data?
Consists of raw facts and figures with no meaning attached
What is information?
Data that has been processed, or data with meaning.
What does an information system do?
Processes data and produces information
What is a bit
A value of 0 or 1
How many bits in a byte
8 bits
How many bits is a nibble
4 bits
How many bytes in a kilobyte
1024 bytes
How many kilobytes in a megabyte
1024 kilobytes
How many megabytes in a gigabyte
1024 megabytes
How many gigabytes in a terabyte
1024 gigabytes
What are integer numbers
Positive or negative whole numbers with no decimal of fractional values
What are real numbers
Positive or negative whole numbers with decimal or fractional values
What is pixel
Smallest unit of a digital image
What is image resolution
Quality of the image, the greater the number of pixels in an image the higher the resolution and sharpness of the image
What are bitmap graphics made up of
A grid of pixels
What is a bitmap graphics image
Very complex
What is a bitmap graphics file size
File size can be very large as they have to store every detail
Are bitmap graphics compressed?
Yes, bitmap images are compressed to reduce file size but this may result in a loss of quality
What is pixelation?
Pixelation can occur when you zoom in to enlarge a bitmap image - this is why bitmap images are poor quality when enlarged too much
What are vector based graphics?
Not made up of a grid of pixels and store information about the compression that make up an image. EG. Lines, curves and shapes
What do vector based graphics not depend on
Resolution for quality
What is streaming
A process that allows a video to be viewed right away in website or app
What is a buffer
Buffer is an allocated part of memory that is used to store a downloaded part of video before it is watched
What is an analogue signal
Continuous varrying signal that represents a physical quantity such as sound
