What does "lossy" refer to in file types?

The term "lossy" refers to a characteristic of files that lose some quality or data during the process of compression or conversion. This process often involves removing certain elements that the algorithm deems unnecessary to reduce file size. For example, in audio and video files, lossy compression may discard frequencies that are less perceptible to the human ear or visual data that is less likely to be missed by viewers.

This characteristic is essential to understand as it highlights the trade-off between file size and quality; while lossy formats are more efficient and create smaller files that are easier to store and transmit, they do sacrifice some detail and fidelity in the process. Examples of lossy file formats include MP3 for audio and JPEG for images. This understanding is crucial when choosing the appropriate file format for specific applications, especially when storage space or bandwidth is a concern.