Which term describes the process of reducing the amount of data in a file so that it takes up less storage space?
Compression
What is meant by lossless compression?
The file size is reduced but none of the original data is lost
Which term describes a method that reduces the size of a file by permanently discarding some of the original data, which can lower the quality of the file?
Lossy compression
What is meant by decompression?
The compressed file is restored to its original size and content
Which term describes the visible mistakes, such as pixelation, that appear when too much of the original data has been removed from an image or video?
Digital artefacts
What is meant by a codec?
Software that encodes data during compression and decodes it when the file is opened
Why must a word-processed document be compressed using lossless compression?
So the contents are exactly the same after uncompressing
A photo is compressed very heavily using lossy compression. What is most likely to be noticed?
Digital artefacts, such as pixelation, in the photo
A company compresses the images and videos on its website. What is the main benefit for visitors?
The pages load quickly because the files download faster
How does lossy compression usually compare with lossless compression?
Lossy reduces the file size much more than lossless
Which file would normally be stored using lossless compression?
A zip file containing a set of documents
As the level of lossy compression applied to a file increases, what happens?
More of the original information is lost from the file
A video production company keeps a large library of video clips. Every clip is compressed before it is stored. What is the main benefit of this?
The clips take up less storage space
A software company compresses the program files for a computer game before customers download it. Why must lossless compression be used?
So the program code is exactly the same after it is uncompressed
A music track is compressed using lossy compression and the file is much smaller, but most listeners cannot hear any difference from the original. Why is this?
Only a small amount of the original data was removed
A film is compressed before it is made available on a streaming service. Why is this done?
So the film can be sent over the Internet without buffering
A wildlife photographer keeps the original high quality versions of her photos. Why would she store these using lossless compression rather than lossy compression?
So that no detail from the original photos is lost
We use cookies to enhance your experience. You can manage your preferences or learn more in our Cookie Policy.