My first guess is that they are counting visits differently. Webalizer I am 99% sure counts the number of total gets/posts. Â AWStats might be trying to actually count visits, so it may being trying to combine gets/posts that are from the same source IP address that are all coming in at the same time.
Remember, when you get a web page, there are multiple gets.  A get is a hit, but 10 gets to retrieve  all information to render a single page is a visit.
Honestly, for most people looking for a stats program, Google Analytics is awesome and takes very little system resources on your webserver (since you don't host it). Â Nothing to break, nothing to maintain, and very detailed reports.
Web development includes all aspects of presenting content on intranets and the Internet, including delivery development, protocols, languages and standards, server software, browser clients, databases and multimedia generation.