Topic 1: Digital Data Flashcards
What is data
Data is raw facts and figures which has not been processed and has no meaning
What is information
Data that has been processed and therefore has meaning and context
What is the difference between data and information
Data is raw facts and figure which has no meaning whereas information is data that has been processed and given meaning and context
1 Bit =
1 Nibble =
1 Byte =
1 Kilobyte =
1 Megabyte =
1 Gigabyte =
1 Terabyte =
1 Bit = 1
1 Nibble = 4 bits
1 Byte = 8 bits
1 Kilobyte = 1024 bytes
1 Megabyte = 1024 kilobytes
1 Gigabyte = 1024 megabytes
1 Terabyte = 1024 gigabytes
What is a pixel
Smallest area of a digital image that can be edited on a graphic
Features of a pixel
Each pixel has its own colour
When combined pixels form an image
Each pixel is stored as a series of binary digits
What is resolution
The measure of the quality of an image. The higher the resolution the better the quality of an image.
What is resolution measured in
DPI - Dots per inch
Disadvantages of resolution
High overall image loading and processing times on computers
Higher overall image file transfer times across communication links
What are bitmap graphics
Bitmap graphics are made up of pixels which can provide high quality photos and millions of colours
What is
JPEG
TIFF
GIF
Joint photographic expert group
Tagged image file format
Graphical interchange format
What is a thumbnail
A thumbnail image is smaller version of an image. You click the thumbnail to display the full version
Advantages of thumbnail
Reduces loading time
Shows a preview of the image
What is a vector based image
Vector graphics are made up of mathematical equations unaffected by scaling
Vector image features
Image can be resized without loss of quality
Image is made up of objects defined by equations
Objects can be edited
Image quality doesn’t depend on res
Suitable for diagrams and symbols
Bitmap image features
File is made up of a grid of tiny pixels
high quality images
can edit individual pixels
When stretched the image can become blurry or pixelated
What is streaming
Streaming involves initiating the playing of a video shortly after the first few seconds of the video file have downloaded, allowing the video to be watched in “real time”
Advantages of streaming
Allows the user to watch the video as it downloads
Sucessive segments downloaded but not saved
What is a buffer
A part of memory used to store a downloaded video before it is watched
Computers store data in what format and convert to what
Computer stores data in digital format however we hear in analogue so ADC, digital to analogue conversion is necessary.
What is an analogue signal
Continuous signal, that represents a physical such as sound temp or light
What is digital signal
A binary signal with 1s and 0s as values
Explain the ADC process
Sound input
Analogue to digital convertor
Computer can process the data
Digital to analogue converter
Sound output to speaker
What is sound sampling
Regularly measuring the voltage of signals
