[thelist] searching using postal codes in the USA

[Bird]

Hi,
A client asked me the following and don't really know how to explain
simply what his website would need. I am a designer and not experienced
enough to explain to him what technologies would be needed. If anyone
could please post a simple reply i.e., is it a script?, do we employ a
database? etc that would be so helpful and I would learn something too!
And any urls are always welcome!

The client asked:
"How does a website provide search information in the USA using postal
code and within certain miles of where a person doing the search is
living ?"

TIA
Lisa