Webalizer unique visitors are different from awstat unique vistors

[BianchiDude]

Webalizer total unique visits are: 2,003
AWstats unique visits are: 159

Why are these different? How many unique visitors did I get?

[chirpy]

They'll always be different. There's no such thing as a "visitor" as far as HTTP is concerned. The stats packages make the concept up and they do it in different ways and over different time intervals. That's why you should stick to one stats package and compare like for like.