Awstats, Webalizer or Google Analytics these are the three most common methods used to gather visitor stats for determing the amount of visitor numbers to your website and also to monitor which web pages are attracting the most visitor numbers.
Awstats and Webalizer are found in your websites CPanal and Google Analytics requires a code to be placed on all your web pages that you want to monitor website users.
While Awstats, Webalizer and Google Analytics gather visitor numbers that move through your website, each one of these statistics gathers collect visitor information in a very different way, as the point of data collection is not the same with each of the data collectors and understanding how each method works will help you to determine the true amount of visitors that are using your website.
Awstats is a program located within your Cpanal and interprets your logfiles to count the amount of visitors to your website, it counts the visitor with the visitors ip address and in doing so can determine if a visitor is a human or if the visitor is a user agent such as a Google bot that index your website content, Awstats will give you a vast amount of information about your visitors, you can use it to determine how much bandwidth your visitors and bots are using, and from where they are visiting from, the ip address of each visitor and how long they were on your website.
Webalizer is also located in your CPanal and works in a similar way to Awstats by collecting information from your servers logfiles, however with Webalizer it does not determine whether a visitor is a human or if the visitor is a robot or Google bot, and by not separating the visitors into Human visitor or robot visitor the visitor number count will always be significantly higher than the visitor numbers counted by Awstats, so your numbers will not be unique visitors but a mix of Human visitors and Google bots.
Google Analytics works in a totally different way than Awstats or Webalizer, with Google Analytics you need to sign up with Google to get a Java script code that is inserted into the web pages of your site that you want Google to monitor visitor numbers on, the problem with Google Analytics is some people block Java Script in there browsers as they are scared of malicious code and when the Java Script is blocked Google Analytics will not count that person as a visitor so you will get deflated visitor numbers, on the upside Google does not count there crawlers and search engine bots and the Google Analytics console provides a vast amount of information about your website visitors.