Which storage feature works by looking for repeated information within a file and then replacing that information with a shorter string?
A Compression
B Capacity on demand
C Compaction
D Sanitization
The correct answer and explanation is:
The correct answer is A: Compression.
Explanation:
Compression is a storage technique that reduces the size of data by finding and eliminating redundancy within files. It works by identifying repeated patterns or repeated information and replacing these with shorter representations, often called codes or tokens. This process helps save storage space and can also speed up data transmission because fewer bits are needed to represent the same information.
There are two main types of compression:
- Lossless Compression: This type preserves all the original data perfectly. When the data is decompressed, it returns exactly to its original form. Lossless compression uses algorithms that detect repeated sequences and replaces them with shorter references without losing any information. Examples include ZIP files and PNG images.
- Lossy Compression: This type reduces data by removing some details considered less important, often used in multimedia like JPEG images or MP3 audio. However, this is not the main focus here, since the question is about replacing repeated information with shorter strings, which is a hallmark of lossless compression.
Why the other options are incorrect:
- B: Capacity on demand
This is a feature where storage capacity can be expanded dynamically as needed, but it does not involve reducing the size of files by finding repeated information. - C: Compaction
Compaction typically refers to the process of rearranging data to reduce fragmentation or consolidate free space in storage media. It does not inherently involve replacing repeated data with shorter strings. - D: Sanitization
Sanitization refers to securely erasing data so that it cannot be recovered. It is a data destruction process, not a data reduction or compression technique.
Summary
Compression works by scanning a file for repeated sequences or patterns and substituting these sequences with shorter codes or strings. This reduces the amount of storage space needed and often enhances transmission efficiency. It is widely used in data storage and transmission systems to optimize resource use without losing the original information, especially in lossless compression scenarios.