The compare "If" NaviCommand Definition help!!!

Hey guys, I need some help here, I'm studying further into Scenarist's capabilities and I see there's a section of the NaviCommand called 'Compare', now I am really not familiar with using that...

I would like to know what the (&, <=, >=, !=, etc.) stands for and how they work, and practically every detail for my understanding, please help...

Thanks Guys :confused: