At this point, your web designer will attend to the final details and test your web site. They will test things such as the complete functionality of forms or other scripts, as well as final testing for last minute compatibility issues (viewing differences between different web browsers), ensuring that your web site is optimized to be viewed properly in the most recent browser versions.
A good web designer is one who is well versed in current standards for web site design and development. The basic technologies currently used are XHTML and CSS. As part of testing, your designer should check to be sure that all of the code written for your web site validates. Valid code means that your site meets the current web development standards. This is helpful when checking for issues such as cross-browser compatibility as mentioned above.