---
title: "Lossy Data Compression — AP CSP Definition & Exam Guide"
description: "Lossy compression shrinks files by permanently removing less important data. Learn how AP CSP tests it in Topic 2.2 and when to pick it over lossless."
canonical: "https://fiveable.me/ap-comp-sci-p/key-terms/lossy-data-compression"
type: "key-term"
subject: "AP Computer Science Principles"
---

# Lossy Data Compression — AP CSP Definition & Exam Guide

## Definition

Lossy data compression is a method of reducing file size by removing unnecessary or less important information. Unlike lossless compression, some data may be permanently lost during this process.

## Related Study Guides

- [2.2 Data Compression](/ap-comp-sci-p/unit-2/data-compression/study-guide/21yLa92Ec2potY7nGQfu)

## Review

### Related Terms

- JPEG: JPEG (Joint Photographic Experts Group) is a commonly used lossy compression format for images. It selectively discards certain image details to achieve higher compression.
- MP3: MP3 (MPEG Audio Layer-3) is a popular lossy audio compression format. It removes sounds that are less perceptible to human ears, resulting in smaller file sizes.
- Bitrate: Bitrate refers to the amount of data processed per unit of time in a compressed file. In lossy compression, lower bitrates often lead to more significant data loss and lower audio/video quality.