Web Design/Development vs Web Applications Development

Web Design has to do primarily with the look and feel of web pages, its more graphic design based.
Web Development has to do with the logistics of making those pages.
Web application development has to do with making applications that run behind or underneath web pages (and many times also the user interfaces as well.) C#.net, PERL, CGI or any other server side languages tend to fall under this.

Those titles are not exclusive though, and I would think Web Development would be inclusive of the others.