Many people confuse the role of a web designer, web developer, and webmaster. This is understandable since many web designers claim to provide developer-like services (e.g. configuring web-based applications, creating databases, writing scripts, etc.) and novice designers sometimes do not consider what happens following site completion. While a web developer may be fit to program your online shopping cart system, he or she may be too expensive to use for day to day maintenance. On the other hand, your website may be entirely created in Macromedia Flash™, but your current webmaster may not have the software or source files to manipulate it. Another common mistake is to assume that in-house personnel have the time or training to complete site maintenance.
Although your Internet Techonology (IT) Department may be great at internet security and networking, only a small (albeit important) part of web design and maintenance fall under these skill sets. Therefore they may be under qualified to perform web design or webmaster duties.
There are several fields within Computer Science, and computer knowledge within one area does not constitute knowledge in another.