There are currently 3 products available they are Web Designer 7, Web Designer 7 Premium, and Website Maker MX.  Website Maker MX is online software so in order to build or edit a web site you need to go online to use the software.  the two Web Designer versions reside on your computer.  In terms of features and design flexibility, Web Designer 7 Premium is the most robust, followed by Website Maker MX and finally Web Designer 7 is the most basic version of the 3.

There is a PDF comparison of the 3 products with all the features at this link  http://www.magix.com/us/website-maker/detail/

I hope this helps