As far as I am aware it is a little bit of a "wooly" position, but in general I believe it to be the type of person who determines the requirements, whether they be hardware, software or just the definition of the data types to be used within the inter/intranet infrastructure. For example, when I am developing a storage system for any of our dot.com customers I have to take into account the data structures and types that will be being transferred in and out bound and then determine the best possible packages and hardware (including features) that will cater for today as well as allow growth ans sustainability for the future without to many changes of strategy or direction. Thus providing for uptime, performance and reliability with security.
hope this makes a sense in a small way
