What is web site usability?

It is that part of development of a site thanks to which the client will come on your resource again and again.

If you have several cups, you drink tea from most handy. So users of the Internet - come on those resources that are most handy in use, on which they receive the information and operate with it on the hoof.

The department of usability-optimization is occupied with transformation of a usual site into the handy and powerful tool.