Web design is the actual creation of the initial web site.
Web maintenance is the updating and changing of content on that site.
The web design contract is separate from the web maintenance or web master contract. As stated on Ad-graphic Web Design's pricing page, minimal changes to a web site will not be assessed.
For example, if your e-mail address changes and you want it corrected on the web page, you will not be charged. Simply e-mail your request.
However, if you expect your site to change frequently, a maintenance agreement is highly recommended.