Portable Network Graphics (PNG) is a lossless image compression format that internally works similarly to a ZIP file (using the DEFLATE algorithm). It's a good choice for images that contain solid blocks of color, and it has a higher image quality (with more colors) than the old Graphics Interchange Format (GIF).
PNG supports transparency in all modern browsers, so you should use it instead of GIF for static images. This is not a problem unless you need to support Internet Explorer 6, in which case, this is probably the least of your troubles. PNG also supports animation with Animated Portable Network Graphics (APNG) files. These are like animated GIFs but of a much higher quality. Unfortunately, only Firefox and Safari support APNGs. ...
