I have AWStats provided my hosting service provider. I have google analytics as well setup. But both show different statistics whom should I trust? Whats more accurate of these two? Should I use something else for getting accurate statistics.
They measure in different ways. AWStats uses analyzed server logs, and they include crawlers and bots, as well as end users with JavaScript disabled and Google Analytics opt-out users, none of which Google Analytics measures.
AWStats constructs visits from a combination of hits in the server logs from their IP address, so they don't follow a user who visits from multiple locations, or who has a dynamic IP address, and they count multiple users from the same IP address as being the same visitor. Google Analytics uses browser-specific cookies to track visitors multiple times in multiple locations. Both can have a tendency to either inflate or deflate numbers. So, server logs could count multiple people on the same network as the same person, but they also double count as you move around, and have no idea how to deal with dynamic IP addresses. Google Analytics can't track one person across their multiple browsers.
So, the right answer, in general, is that no analytics tracking is ever 100%, that the numbers should always be treated as approximations, and that every number you look at should be considered in the context of how its tracked and only compared to numbers gathered in similar contexts. The general trend is that AWStats overstates numbers and that Google Analytics understates them, but that's not an ironclad rule.