If you want your graphics to be better quality, follow these easy tips.
.gif is the image format commonly used for images on the Internet. They can be transparent and animated images. Most graphics can be saved as a .gif without too much color loss if you use 255 colors when saving. They don't take up much space, unless you have animated images with lots of frames. If you're using Paint, don't save as .gif; it'll get spotty and a lot of color loss because you can't optimize like on other programs.
.jpg/.jpeg are best for photos. You should optimize when you save for better quality, since they can sometimes get blurry when you upload them.
.png are very high quality. They look exactly the same on the internet as they do in your graphics program, without color loss. The downside is that they take a while to load, especially on dial up. Transparency is supported, but doesn't display in older versions of IE.
.psd stands for Photoshop Document. A .psd file has all of the layers saved, so when you reopen the file later, you can edit whatever you were working on. You might have seen sites that offer PSDs - cropped images, usually of people, with a transparent background.
.cur are used for regular cursors.
.ani are used for animated cursors. Animated cursors only work in IE and similar browsers.
.bmp I wouldn't recommend using .bmps because they take a while to load, take up a lot of space, and they don't show up on some computers. If you're using Paint, save as a .png instead.
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