I need to understand the difference in exporting gifs using web pallete vs optimized pallete.

When I use web pallete the image is distorted (heavily pixelized) when viewed at lower resolutions on larger screen monitors. So, I want to get a better understanding of the optimized pallete to decide if I should use it.

Also, when using the optimized pallete, there are 3 choices available for the number of bits: 8, 4, and 1. However, you can limit the number of colors regardless of which bit size you use, and that effects a file size. I would like that explained as well.

I think what I may need are some technical documents on how Xara exports gifs.

Thanks in advance for any info that you may be able to pass on to me.

JudyG