Strong typography together with strong photography play an important role in any websites' design.
The introduction of CSS to web design allowed designers to use typography in a way that previously could only have been achieved by rendering the text as a graphic. This has casued typography to become an important facet of the web designs toolkit.
There are, however, still limitations. Fonts can only be used if they are installed on the web browsers computer, this means that to use a font reliably it must be either one of the standard fonts installed with windows or on the mac.
A list of web safe fonts can be seen here: Fonts Common to all versions of Windows & Mac equivalents