fixed resolution?

websites resolutions these days are width fixed and auto high.... but is it really needed to have fixed width and high?

Depends on the site and its intended audience. Some respond better to fixed widths, some liquid, some a hybrid of the two.

So there's really no answer to that question. Not a universal one, anyway. Nor should there be.

i find that most sites are fixed width, but auto hight to support any amount of content - forums and blogs are good examples, with every post it gets higher, width stays the same