AP Computer Science Principles Flashcards: Data Compression

What this deck covers

This deck focuses on Data Compression, giving you a quick way to review the definitions, rules, and examples that matter most for AP Computer Science Principles.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Which compression type typically results in smaller file sizes?

Answer: Lossy compression. Removing data allows for greater size reduction.

Flashcard 2: Which type of compression is used in ZIP files?

Answer: Lossless compression. File archives require perfect data preservation.

Flashcard 3: Identify a disadvantage of lossless compression.

Answer: Larger file sizes compared to lossy compression. Perfect preservation requires more storage space.

Flashcard 4: Which type of data is less compressible?

Answer: Data with high entropy. Random data lacks patterns for compression algorithms.

Flashcard 5: What is the primary trade-off in lossy compression?

Answer: File size versus quality. Core decision in choosing compression settings.

Flashcard 6: What is data compression?

Answer: Data compression reduces file size by encoding information more efficiently. Essential technique for managing storage and bandwidth efficiently.

Flashcard 7: What is the primary challenge of data compression?

Answer: Balancing compression efficiency with data quality. Optimizing both compression ratio and acceptable quality.

Flashcard 8: What is a common algorithm used for lossy compression?

Answer: The JPEG algorithm. Widely used for image compression with quality loss.

Flashcard 9: What does 'decompression' mean?

Answer: Restoring compressed data to its original form. Process of expanding compressed data back to original.

Flashcard 10: Identify a use case for lossy compression.

Answer: Streaming audio or video where quality loss is acceptable. Real-time applications can tolerate some quality loss.

Flashcard 11: In which scenario is lossless compression favored?

Answer: When data integrity is critical, such as text files. Perfect reconstruction is essential for text documents.

Flashcard 12: In which scenario is lossless compression favored?

Answer: When data integrity is critical, such as text files. Perfect reconstruction is essential for text documents.

Flashcard 13: What is lossless compression?

Answer: Compression that allows original data to be perfectly reconstructed. No information is permanently lost during compression.

Flashcard 14: What is entropy in the context of data compression?

Answer: Measure of randomness or disorder in data. Higher entropy means less predictable, harder to compress data.

Flashcard 15: Identify a file format that uses lossy compression.

Answer: JPEG. Common image format that sacrifices quality for size.

Flashcard 16: Identify a benefit of smaller file sizes.

Answer: Faster data transmission. Reduced file sizes improve network transfer speeds.

Flashcard 17: What is Huffman coding?

Answer: A lossless data compression algorithm using variable-length codes. Assigns shorter codes to more frequent characters.

Flashcard 18: Which compression is reversible, lossy or lossless?

Answer: Lossless compression. Only lossless compression preserves all original data.

Flashcard 19: Which type of compression is used in ZIP files?

Answer: Lossless compression. File archives require perfect data preservation.

Flashcard 20: Which type of compression is used in MP3 audio files?

Answer: Lossy compression. Audio quality reduction is acceptable for smaller files.

Flashcard 21: What is entropy in the context of data compression?

Answer: Measure of randomness or disorder in data. Higher entropy means less predictable, harder to compress data.

Flashcard 22: What is the primary goal of data compression?

Answer: To reduce the size of data files. Fundamental objective of all compression algorithms.

Flashcard 23: Identify a use case for lossy compression.

Answer: Streaming audio or video where quality loss is acceptable. Real-time applications can tolerate some quality loss.

Flashcard 24: What is Huffman coding?

Answer: A lossless data compression algorithm using variable-length codes. Assigns shorter codes to more frequent characters.

Flashcard 25: What does the term 'compression ratio' refer to?

Answer: Ratio of the size of the compressed file to the original file. Lower ratios indicate better compression efficiency.

Flashcard 26: What is the impact of compression on image quality?

Answer: Potential loss of detail in lossy compression. Lossy algorithms remove visual details to reduce size.

Flashcard 27: Which compression type typically results in smaller file sizes?

Answer: Lossy compression. Removing data allows for greater size reduction.

Flashcard 28: What does MPEG stand for?

Answer: Moving Picture Experts Group. Standards organization for audio and video compression.

Flashcard 29: What does the term 'compression ratio' refer to?

Answer: Ratio of the size of the compressed file to the original file. Lower ratios indicate better compression efficiency.

Flashcard 30: What is run-length encoding (RLE)?

Answer: A simple form of lossless data compression based on runs of data. Replaces repeated values with count and value pairs.

Flashcard 31: What is a common algorithm used for lossless compression?

Answer: The Lempel-Ziv-Welch (LZW) algorithm. Dictionary-based algorithm for efficient lossless compression.

Flashcard 32: Which type of compression is used in MP3 audio files?

Answer: Lossy compression. Audio quality reduction is acceptable for smaller files.

Flashcard 33: What is lossy compression?

Answer: Compression that reduces file size by removing some data, losing quality. Trades data fidelity for smaller file sizes.

Flashcard 34: What does MPEG stand for?

Answer: Moving Picture Experts Group. Standards organization for audio and video compression.

Flashcard 35: What role does redundancy play in data compression?

Answer: Higher redundancy increases potential for compression. Repeated patterns enable more effective compression.

Flashcard 36: Which type of data is more compressible?

Answer: Data with low entropy. Predictable data contains patterns for compression.

Flashcard 37: What is the primary challenge of data compression?

Answer: Balancing compression efficiency with data quality. Optimizing both compression ratio and acceptable quality.

Flashcard 38: Identify a use case for lossless compression.

Answer: Medical imaging where data integrity is crucial. Critical applications require perfect data preservation.

Flashcard 39: Identify the two main types of data compression.

Answer: Lossy and lossless compression. These represent the fundamental approaches to data reduction.

Flashcard 40: Which type of data is less compressible?

Answer: Data with high entropy. Random data lacks patterns for compression algorithms.

Flashcard 41: Identify a disadvantage of lossy compression.

Answer: Loss of data quality and fidelity. Irreversible information loss reduces file quality.

Flashcard 42: What is a common algorithm used for lossless compression?

Answer: The Lempel-Ziv-Welch (LZW) algorithm. Dictionary-based algorithm for efficient lossless compression.

Flashcard 43: What is a common algorithm used for lossy compression?

Answer: The JPEG algorithm. Widely used for image compression with quality loss.

Flashcard 44: Identify a file format that uses lossless compression.

Answer: PNG. Image format that preserves all original pixel data.

Flashcard 45: What is a bit rate?

Answer: Number of bits processed per second in a compressed file. Determines data transmission speed and quality.

Flashcard 46: Identify a disadvantage of lossless compression.

Answer: Larger file sizes compared to lossy compression. Perfect preservation requires more storage space.

Flashcard 47: What is a bit rate?

Answer: Number of bits processed per second in a compressed file. Determines data transmission speed and quality.

Flashcard 48: What is the effect of compression on data transmission speed?

Answer: Compression generally increases data transmission speed. Smaller files transfer faster over networks.

Flashcard 49: Name a factor that affects the choice of compression method.

Answer: The importance of data fidelity. Critical consideration when selecting compression type.

Flashcard 50: How does reducing the bit rate affect file size?

Answer: It decreases the file size. Lower bit rates mean more compression and smaller files.

Flashcard 51: What is the primary goal of data compression?

Answer: To reduce the size of data files. Fundamental objective of all compression algorithms.

Flashcard 52: What is a codec?

Answer: A device or program for encoding or decoding data streams. Software that compresses or decompresses digital media.

Flashcard 53: Name a factor that affects the choice of compression method.

Answer: The importance of data fidelity. Critical consideration when selecting compression type.

Flashcard 54: Why is entropy important in data compression?

Answer: Higher entropy indicates less potential for compression. Random data has high entropy and resists compression.

Flashcard 55: Identify a use case for lossless compression.

Answer: Medical imaging where data integrity is crucial. Critical applications require perfect data preservation.

Flashcard 56: What is lossy compression?

Answer: Compression that reduces file size by removing some data, losing quality. Trades data fidelity for smaller file sizes.

Flashcard 57: What is lossless compression?

Answer: Compression that allows original data to be perfectly reconstructed. No information is permanently lost during compression.

Flashcard 58: Calculate the compression ratio: original size 200 MB, compressed size 50 MB.

Answer: 4:1. Original size divided by compressed size: $200 ÷ 50 = 4$.

Flashcard 59: What is the primary trade-off in lossy compression?

Answer: File size versus quality. Core decision in choosing compression settings.

Flashcard 60: Identify a benefit of smaller file sizes.

Answer: Faster data transmission. Reduced file sizes improve network transfer speeds.

Flashcard 61: What is data compression?

Answer: Data compression reduces file size by encoding information more efficiently. Essential technique for managing storage and bandwidth efficiently.

Flashcard 62: What is the result of decompressing a lossy file?

Answer: The file may not be identical to the original. Lossy compression causes permanent information loss.

Flashcard 63: Identify a disadvantage of lossy compression.

Answer: Loss of data quality and fidelity. Irreversible information loss reduces file quality.

Flashcard 64: What is the result of decompressing a lossless file?

Answer: The file is identical to the original. Lossless compression preserves every bit of data.