What is the difference between free & paid for Avast?

Just a quick question, I’m not sure if this has already been asked & answered before. Did have a quick look on the search but didn’t find anything relevant.
But anyway, what I’m wondering is what is the actual difference between downloading Avast off of www.download.com for free, & getting a registration key that will allow me to use Avast for 1 year at no cost; compared to the Avast that I would have to pay £25 so that I can use it for a year? I’ve got the free edition on my friends laptop, & I’m currently using the demo of pro which lasts for 60 days, but I haven’t seen any differences between either of them so far.

James.
Just a quick answer. ;D http://www.avast.com/eng/av4_version_comp.html

Also feature descriptions: http://www.avast.com/eng/avast_4_professional.html items marked “(Professional Edition only)”.

Thank you ;D

The first link helped a lot :slight_smile: