Here is what you get with the Free & Pro versions:
Anti-Virus & Anti-Spyware
Protection against viruses, spyware, adware and trojans

LinkScanner Active Surf-Shield
Protects in real time against poisoned web pages while you’re surfing

LinkScanner Search-Shield
Real-time safety ratings for all search results in Google, Yahoo and MSN/Live search

AVG Security Toolbar
Easy access to LinkScanner tools, built-in search capability

The Pro Version also has:

Web Shield
Screens your downloads and prevents accidental infections through IM chats

Anti-Rootkit
Protection against hidden threats that deliver malicious content

Free Support
Free support and service around the clock and across the globe