Digital Data- Chapter 1 Flashcards
What is Data?
Data is raw, unorganized facts that needs to be processed. Data has no meaning.
What is Information?
Information is when data is processed, organized, structured, or presented in a given context so as to make make it useful/meaningful.
REPRESENTING IMAGES
What is a Pixel?
A pixel, usually a square, is the smallest unit of a digital image that can be displayed and edited on a computer screen.
REPRESENTING IMAGES
What is Image Resolution?
The image resolution tells us the quality of an image, the more pixels the higher the quality and sharpness of the picture.
REPRESENTING IMAGES
What is a Bitmap?
Bitmap is an image made up of individual bits where each bit represents one pixel.
REPRESENTING IMAGES
What is a Vector?
Vector graphics are images that are completely described using mathematical definitions.
What is Streaming?
Streaming means listening to music or watching video in ‘real time’, instead of downloading a file to your computer and watching it later.
What is Buffering?
Buffering: preloading data into a reserved area of memory it is called buffering. ‘The Buffer’ is the name for the area in memory where data is pre-loaded.
Advantages and Disadvantages of Streaming
Advantage: accessible, doesn’t take up storage Disadvantage: Costly, Need internet connection
COMPRESSION
Data needs to be compressed to make files easier to send or store.
COMPRESSION
Data Compression
Data Compression is used to convert digital data to as small a size as possible while still maintaining the quality of the data contained in the file.
COMPRESSION
Lossy Compression
Lossy Compression reduces the file size by removing data such as taking colors out of a photo. E.g. JPEG. Data is lost forever
COMPRESSION
Lossless Compression
Lossless Compression maintains the quality of the file, so no data is lost. e.g. Zip
REPRESENTIG SOUND
Sample Rate
This is the number of audio sound samples captured every second to represent the sounds digitally and is measured in Hertz(H).
REPRESENTING SOUND
Bit Depth
Bit Depth is the number of bits used to store each sound sample. Higher quality sound requires a higher bit depth.
REPRESENTING SOUND
Bit Rate
Bit Rate refers to the quantity of data measured in bits that is processed in a given amount of time. This is usually in kilobits per second.
DATA TYPES
Numeric
Integer Numbers: an integer can be a positive or negative whole number, which has no decimal or fractional parts.
Real Number: real numbers include whole numbers and numbers with decimal/ fractional parts. Real numbers can be positive or negative.
DATA TYPES
Date/ Time
This determines the way that the date or time appears when it is displayed or printed by a computer.
DATA TYPES
Character/ String
Character: A character is a single letter or digit represented by codes from the character set used by the coumputer.
