Adlogger will tell you which people moved their mouse pointer over your ads, which doesn't necessarily correspond to clicks. There's always an element of doubt when deciding who clicked what ad and where.
Yes the most of the times. If some user search for "your keyword" and comes to your website and clicks to an ad, the adlogger shows you that. However if the same user comes with the same keyword but he views 5,6 other pages and then he clicks on an ad you will not know the keyword that reffer him to your website but you will know at which page the click was made.
That's not totally true. Maybe Adlogger isn't the most accurate form of logging your clicks, but it doesn't log a click when you put your mouse over the ad. It does, however, log a click if you right-click an ad, for example.