There really is nothing like practical experience of installing the program and using it, checking each of the various providers and how they can be tweaked, avast is a very configurable, flexible anti-virus.
I have this schoolwork where we´re going to look up some facts from different anti-virussoftwares that are out there.
and I got the subject to look up how an anti-virus works.
For the most part anti-viruses use known signatures of viruses in order to detect them, Virus Pattern Signature files (VPS), some also use Heuristics, looking for suspicious activity/patterns, etc.
avast generally uses the VPS file to detect viruses except for the email scanning when it also uses Heuristics. There are two broad types of scan: on-access (often called resident) scanning, where a file is scanned when a program wants access to it, so before the file is executed it is scanned; the other is called on-demand, where you the user initiate the scan and there are different ways to do this.
In some of the resident scanners, avast! also uses a means of scanning the files from the internet and email before they are actually saved on to your HDD or email inbox. So if an infected file is found it can be deleted before it is saved to the HDD or inbox. This is better/easier than having to try and remove the file once it has been saved to the HDD or inbox.
Good luck with your project.
