What Does 'Compression (Data Compression)' Mean?

What is Compression (Data Compression)?
Photo by Tomas Sobek on Unsplash

Data compression is a technique used to represent data in a more compact form in order to reduce the amount of storage space required or to transmit the data more efficiently over a network. The goal of data compression is to represent the same information using fewer bits without losing any of the original data.

Lossless compression and lossy compression are the two main methods of data compression.

  • Lossless compression algorithms aim to reduce the size of the data while still preserving all of the original information, so that when the data is decompressed, it is exactly the same as the original data.
  • Lossy compression algorithms, on the other hand, allow for some loss of information in order to achieve a higher level of compression.

There are several different algorithms and techniques used for data compression, each with its own strengths and weaknesses.

Some common examples include:

  • Huffman coding: This is a lossless data compression algorithm that works by replacing frequently occurring symbols with shorter bit sequences, and less frequently occurring symbols with longer bit sequences.
  • Run-length encoding: This is a lossless data compression algorithm that works by replacing sequences of identical symbols with a single symbol and keeping track of the number of times the symbol appears.
  • LZW (Lempel-Ziv-Welch) compression: This is a lossless data compression algorithm that works by creating a dictionary of previously seen patterns and using the dictionary to replace repeating patterns in the data with a reference to the dictionary entry.
  • JPEG (Joint Photographic Experts Group) compression: This is a lossy data compression algorithm commonly used for images. It works by reducing the resolution and color depth of the image, as well as by removing certain non-essential image data.
  • MP3 (MPEG-1 Audio Layer 3) compression: This is a lossy data compression algorithm commonly used for audio. It works by removing certain parts of the audio signal that are not perceived by the human ear, as well as by reducing the bit rate of the audio.

Data compression can be very useful in a variety of applications, including reducing the size of files for storage and transmission, improving the performance of data transfer over networks, and reducing the amount of data that needs to be processed by a computer.

But it is important to consider the trade-offs between the level of compression achieved and the loss of information that may occur, particularly when using lossy compression algorithms.

More information

File compression is a technique for reducing the size of a file in order to save space on a hard drive or to make it easier to send over the internet. There are many different algorithms and file formats that can be used for file compression, including popular formats such as ZIP, RAR, and GZIP.

Media compression, on the other hand, refers to techniques used to reduce the size of audio, video, and image files, while still maintaining a reasonable level of quality. Media compression is often used to make it more practical to store and transmit large media files, for example, movies and high-resolution images.

There are several different algorithms and file formats that can be used for media compression, like the well-known formats MP3, MP4, and JPEG.

Both file compression and media compression rely on finding ways to represent the same data with fewer bits.

This can be achieved by identifying and removing redundancy in the data or by using techniques such as lossy compression, which involves discarding some of the data in order to achieve a higher level of compression.

File compression is typically used to compress individual files or groups of files, while media compression is often used to compress audio and video streams in real-time as they are being transmitted or recorded.

Both file compression and media compression can be performed using software tools, or they can be built into hardware devices, namely routers, modems, and media players.