How do I create transparent gifs with Photoshop 4 0?

There have been occasional claims that PNG files are generally larger than GIFs. PNG files can indeed be much larger than GIF files in situations where a GIF and a PNG file were created from a high-quality master image, as PNG is capable of storing more color depth and transparency information than GIF, and due to the fact that GIF encoders often simplify complex images resulting in a lossy result. However, identical 8-bit (or lower) image data data rendered in PNG and GIF should yield similar sizes. Misinformation about PNG efficiency can generally be traced back to poor PNG support in older versions of some image manipulation programs, such as Adobe Photoshop that did not optimize PNGs for reduced color palettes by default.