Digital Data Flashcards
What is Data?
Unprocessed facts or figures that, on their own, have no meaning
What is information?
When data is entered into a computer system and is processed, it becomes information, or ‘data with meaning’
In what format does the computer store data?
Binary Format
1 nibble = ?
4 bits
1 byte = ?
8 bits
1 kilobyte= ?
1024 bytes
1 megabyte= ?
1024 kilobytes
1024 megabytes=?
1 Gigabyte
1024 Gigabytes=?
1 Terabyte
What is the Data type numeric
An integer number that can be positive or negative
An integer number that has no decimal or fractional parts
Explain the Data type Date/Time
Long date: displayed as Sunday, April 1, 2018.
Medium date: displayed as dd-mmm-yyyy, e.g. 1-Apr-2018.
Short date: displayed as dd/mm/yyyy, e.g. 01/04/2018.
Long time: displayed as HH:MM:SS, e.g. 13:26:34
Medium time: displayed as HH:MM PM/AM, e.g. 01:26 PM
Short time: displayed as HH:MM, e.g. 13:26
Explain the Data type Character/String
A character is a single letter or digit represented by the codes from the character set.
A string is textual data in the form of a sequence of characters.
What is a pixel?
A smallest unit of a digital image that can be displayed and edited on a computer screen
What is Image resolution
Represents the quality of an image
More pixels = higher quality
What is a Bitmap Image?
Made up of Pixels
Stores details about every pixel on the image
Advantage of Bitmap
Can be compressed which reduces file size
Disadvantage of Bitmap
Storing every pixel means that file size is large
What is a vector image?
stores information about the components that make up a image
What is Streaming?
Streaming allows a video to be viewed on a website without needed to download it
What is Buffer?
When the user if watching a part of a video, a buffer is used to download the next part of the video
What is sample rate?
Number of audio sample captured per second to represent the sounds digitally
What is Bit depth?
The number of bits used for each sound sample
What is Bit rate?
The quantity of data measured in bits that is processed in a given amount of time.
Explain Analogue to Digital Conversion
An analogue signal is a continuous varying signal that represents a physical quantity.
An analogue to digital converter (ADC) will sample a signal at regular time intervals.
Samples are then converted to digital format.
The frequency at which samples are taken is known as the sample rate, measured in Hertz (Hz).
What is Data Portability
Data portability is the ability to transfer data from one computer to another or from one software application to another without having to re-enter the data.
Expand JPEG
Joint Photographic Expert Group
Expand TIFF
Tagged Image File Format
Expand PNG
Portable Network Graphics
Expand GIF
Graphic Interchange Format
Expand CSV
Comma -separated-value
Expand RTF
Rich Text Format
Expand MIDI
Musical Instrument Digital Interface
Expand MPEG
Moving Picture Experts Group
Expand AVI
Audio Video Interleaved
Expand PDF
Portable Document Format
Expand WAV
Waveform Audio File
Expand WMA
Windows Media Audio
Explain Data Compression
Data compression 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
Explain Lossy Compression
Reduces the file size by removing some data, such as reducing the number of colours used in an image.
Explain Lossless Compression
Maintains the quality of the file, therefore no data is lost.
