Is there a specific way to distinguish between an A, B, C and D Class property?

[Kevin Parnella]

Hi,

Good evening. I am a newbie here and I love the conversations.

I would like to get on the same page with real-estate companies or turnkey companies that describe the different classes of properties. How do I know I'm looking at a B class property for example, versus a C- class property for example? I will always run numbers and look at demographics, but I was just wondering if there is a definitive way to address these questions or is there a lot of speculation or difference of opinion between these classes? So if a turnkey company sends me a what they consider a B property, am I going to do my research and rebut their opinion and say it's a class C-?  

thank you