AP Computer Science Principles Flashcards: Data Compression
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 21 cards to help you master important concepts.
Does reducing the number of bits in a file always mean losing information?
No, fewer bits does not necessarily mean less information, as lossless compression allows for perfect reconstruction of the original data.
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All Flashcards (21)
Does reducing the number of bits in a file always mean losing information?
No, fewer bits does not necessarily mean less information, as lossless compression allows for perfect reconstruction of the original data.
What is the primary trade-off when using lossy compression?
The trade-off is that you achieve a significant reduction in data size at the cost of only being able to reconstruct an approximation of the original data.
In what situation is a lossless compression algorithm the preferred choice?
Lossless algorithms are chosen in situations where quality or the ability to perfectly reconstruct the original data is maximally important.
Why can lossy algorithms compress data more than lossless ones?
Lossy algorithms achieve greater compression because they discard some of the original data, whereas lossless algorithms must preserve all information to ensure perfect reconstruction.
What is the key guarantee provided by lossless compression?
Lossless compression guarantees the complete and perfect reconstruction of the original data from the compressed version.
Define lossy data compression.
Lossy data compression algorithms significantly reduce the number of bits stored or transmitted but only allow for the reconstruction of an approximation of the original data.
What two things does the success of a compression algorithm depend on?
It depends on the algorithm itself and the amount of redundancy present in the original data representation.
If you are compressing a text document for legal archival, which compression type should you use?
A lossless compression algorithm should be used, because the ability to reconstruct the original document perfectly is maximally important.
Which type of compression algorithm typically achieves a greater reduction in file size?
Lossy data compression algorithms can usually reduce the number of bits stored or transmitted more than lossless compression algorithms.
What is data compression?
Data compression is the process of reducing the size, measured in the number of bits, of data that is transmitted or stored.
What is the fundamental difference in outcome between lossy and lossless compression?
Lossless compression allows for perfect reconstruction of the original data, while lossy compression only allows for reconstruction of an approximation.
What two factors determine the amount of size reduction achieved by compression?
The amount of size reduction depends on both the amount of redundancy in the original data and the specific compression algorithm applied.
If your highest priority is minimizing transmission time, which compression type do you choose?
You should choose a lossy compression algorithm when minimizing transmission time is maximally important.
To stream a movie online with minimal buffering, which compression type is more suitable?
A lossy compression algorithm is more suitable because minimizing the data size and transmission time is the most important factor.
How does data redundancy affect compression?
The amount of size reduction from compression depends on the amount of redundancy in the original data; more redundancy often allows for better compression.
If your highest priority is data quality, which compression type do you choose?
You should choose a lossless compression algorithm when quality and the ability to reconstruct the original data are maximally important.
What is the essential first step when choosing a compression algorithm for a specific task?
The first step is to compare data compression algorithms to determine which is best in that particular context, balancing needs like file size and data quality.
What does 'reconstruction of an approximation' mean in the context of lossy compression?
It means the data restored after lossy compression is very similar to, but not an identical copy of, the original data.
Define lossless data compression.
Lossless data compression algorithms reduce the number of bits stored or transmitted while guaranteeing the complete reconstruction of the original data.
A company wants to reduce server storage costs for millions of user profile photos. Which compression strategy is likely best?
A lossy compression algorithm is likely best, as minimizing data size is maximally important and a slight loss in image quality is often acceptable.
In what situation is a lossy compression algorithm the preferred choice?
Lossy algorithms are chosen in situations where minimizing data size or transmission time is maximally important.