Compression: Lossy and Lossless

Data files — images, audio, video, and text — can be very large. Compression reduces the file size so that files take up less storage space and can be transmitted more quickly. This lesson covers the two main types of compression: lossy and lossless.

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Why Compress Data?

There are several important reasons to compress data:

• Reduce storage space: Smaller files take up less room on hard drives, SSDs, and other storage media.
• Faster transmission: Smaller files can be sent over the internet or a network more quickly, using less bandwidth.
• Reduce costs: Less storage and bandwidth are needed, which can save money.
• Enable streaming: Audio and video files must be compressed to allow real-time streaming over the internet.

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Lossy Compression

Lossy compression reduces file size by permanently removing some of the data. The removed data is typically information that humans are unlikely to notice.

How Lossy Compression Works