2.3 Data Portability Flashcards
Define data portability.
The ability to transfer data from one system or software application to another without having to re-enter the data.
What is the purpose of data compression?
It converts digital data to as small a size as possible without losing any of the information contained in a file.
Describe bitmapped graphics.
They depend on resolution for quality. The higher the resolution, the larger the size of the graphic and the greater the quality. They cannot be stretched without losing image quality. They can be compressed or saved in other file formats like GIF and JPEG to reduce their size.
Describe vector graphics.
They are not dependant on their resolution for quality, as they are formed from vector objects. They can be stretched or shrunk without losing the quality of the image. This means no matter how many dpi are used on screen or in print, the image will still look the same. Because of their structure, they can generally be saved as smaller files that bitmaps.
Describe a data compression tool and how it works.
WinZip is an example of a data compression tool. It compresses files to a fraction of their size. Files that are compressed in this way are called ZIP files. These files must be compressed before being transferred and then decompressed at their destination before they can be used. It can also be used to compress full folders of information and store them as a single file for emailing or transporting. The destination computer must have the data compression tool so that the file can be extracted or unzipped.
Give 4 ways in which data compression tools are useful.
- When a folder of information is to be emailed as a single file.
- When a user wants to email a large file, it can be reduced in size.
- When a file is too larger for a particular storage media.
- To reduce the amount of storage space taken up by files as they can be stored in compressed format.
What is the difference between lossless compression and lossy compression?
Lossless compression works by removing redundancy, Redundant information is replaced with instructions telling the computer how much identical data repeats. No data is lost and the original file can be reconstructed. Whereas lossy compression works by simply removing information. The original file cannot be recreated because data is lost.
