When working with digital images there are several file formats and file extensions to be aware of. Typically, the most widely used formats include TIFF, JPEG, GIF, and PNG. A brief outline of each is as follows:
JPEG: Images that are saved and displayed as JPEGs are usually the most desirable format destined for online use. These images have very good rates of compression while at the same time offering little sacrifice in image quality. JPEGs are the suggested format for online use.
PNG: This particular format is also another option to use when there is little to moderate compression and little sacrifice of image quality. The problem with this format is that PNG isn't supported on all Web browsers.
GIF: Images using the GIF extension have very little to no compression, provided the image is not too rich in color. This means that as long as there are less than 256 degrees of colors in the image, it will be rendered exactly with no compression. Greater than that amount, the quality of the image will degrade. Along with JPEG, it is a recommended file format.
TIFF: These images are typically uncompressed, which means that though the files will not lose any quality, they will tend to be very large. Consider these files to be used as master imagesfor archival and back-up purposes, not to be used for online posting.