Although graphic design is a major part of website design it is not the same. There is a big difference between the person who designs the shape of a car and the engineers that actually build the car. The engineers are responsible to make sure the car runs, that its parts fit and that it performs and functions the way it is supposed to.
In no way can a graphic designer create a website in the same way that a professional website designer can. In the big scope of website design, the graphic design of the site is just one of the important factors. Other factors include the layout, navigation, coding, programming, development, construction, launching, marketing, search engine optimization, hosting, promotion, and maintenance. Only a reputable and skilled, professional website designer can provide all of these important services.
While a graphic designer may be able to provide a layout, look or branding for your business, he or she will not have the skill and know how to provide the programming, coding and other technical aspects required to build a successful site. This is why finding the right website design firm is so important.