Advanced Placement (AP) Computer Science 2025 – 400 Free Practice Questions to Pass the Exam

The type of data compression that results in the loss of some original data is lossy compression. This method reduces file size by permanently eliminating some information, particularly information that is less likely to be perceived by the human senses, such as subtle color variations in images or higher frequencies in audio.

Lossy compression is commonly used in formats like JPEG for images and MP3 for audio, where a degree of fidelity to the original data is compromised to achieve significant reductions in file size. This makes it particularly useful for streaming and storage where bandwidth and space are limited.

In contrast, lossless compression retains all original data, allowing the file to be reconstructed exactly as it was. Forms of lossless compression include formats like PNG for images and FLAC for audio. Metadata refers to additional information about data, such as its format or type, while iteration refers to repeating a process or set of instructions and does not pertain to data compression.