It is a simple php script that you place somewhere on you website and this script will return the AWStats data as json.
As an example say that you place the script getawstats.php on your site lets call it example.com, then when you access http://example.com/awstats/getawstat.php you can get the following data
{"summary":{"year":"2013","month":"04","lastupdate":"20130410075001","uniques":"27423","visits":"60031","pages":152305,"hits":708106,"bandwidth":118969674567},"days":[{"day":1,"pages":10662,"hits":50642,"bandwidth":4577570523,"visits":5086},{"day":2,"pages":11969,"hits":46479,"bandwidth":3942706134,"visits":6325},{"day":3,"pages":14303,"hits":55780,"bandwidth":8044779500,"visits":6415},{"day":4,"pages":34091,"hits":217563,"bandwidth":47562300844,"visits":9528},{"day":5,"pages":21942,"hits":109844,"bandwidth":18326884056,"visits":7771},{"day":6,"pages":16759,"hits":63628,"bandwidth":11206302251,"visits":6731},{"day":7,"pages":12302,"hits":48495,"bandwidth":8123735971,"visits":4993},{"day":8,"pages":12060,"hits":43136,"bandwidth":7246989597,"visits":5119},{"day":9,"pages":15968,"hits":64832,"bandwidth":8986186671,"visits":6940},........ and so on