What Server is
A host computer on a network. It houses information and responds to requests for information (for example, it houses Web sites and executes their links to other Web sites). The term "server" also refers to the software that makes the act of "serving information" possible. Commerce servers, for example, use software to run the main functions of an e-commerce Web site, such as product display, online ordering, and inventory management (you'll also hear this described as shopping cart technology). A server is the control computer on a LAN, meaning it controls the software, access to printers, and other parts of the network (usually accompanied by workstations that "share the load"). A server may be dedicated (where its sole purpose is to be the server) or non-dedicated (where in addition to being the server, it can be used for basic computing purposes).
The meaning of Web designer
The aesthetic and navigational architect of a Web site, the designer is the person responsible for how the site looks and feels. He or she is the one who takes the heat if the graphics are fuzzy, the links are too light, or something is hard to find on a Web page. Usually this person is trained in the creative side of image development; however, an extensive knowledge of Web-based programming and information architecture is considered fundamental to being a successful Web designer. (That and good client-relationship skills are a must.)