What type of compression does a JPG file use?

JPG (or JPEG) files utilize lossy compression, which is specifically designed to reduce file size by discarding some image data that is deemed less important for the overall visual quality. This method allows for a more significant reduction in file size compared to lossless compression, which retains all the original data but may not reduce the file size as effectively.

In lossy compression, when a JPG image is saved, the software analyzes the image and eliminates certain details that the human eye is less likely to notice. This process is particularly effective for photographic images where slight differences in color and detail can go unnoticed. As a result, while JPG images can achieve smaller file sizes, they can also experience a decrease in quality with repeated saving and compression.

Understanding this concept is crucial for artists and designers who need to balance image quality and performance, especially in web design and digital media where loading times and bandwidth considerations are important.