This is essential to the success of a web site because nothing adds to web page load times like large graphics. Long load times result in very few visitors. A 360 kilobyte image could take two minutes or longer to load on a 28.8 modem and four minutes or more on a 14.4 modem. In the tradition of focusing the site design on the visitor, it is important to remember that every visitor to a site may not wish to wait several minutes for a full screen picture of a favorite rock or tree to download. It is acceptable to include large graphic files in a web site, but they should not be required viewing.
Some optimization requires a reduction in the physical size of an image to fit it better on a page.
In addition, images without any compression are often too large for general web use. Choosing the correct type of compression is also important. The correct compression can drastically reduce file sizes while preserving most of the image quality. Choosing the wrong compression could adversely affect the quality of the image. Language choice is a very important part of designing web pages.