What file formats shold be used for web graphics?
The most commonly used file formats are the GIF (Graphics Interexchange Format, trademark of Compuserve, Inc.) an JPEG (Joint Photographic Experts Group). In more recent years, some designers increasingly use PNG (Portable Network Graphics) because of the support for optional alpha channel for transparency, but majority is still avoiding it because of the lack of browser support. PNG is an extensible file format for the lossless, portable, well-compressed storage of raster images.