What do the property class types mean?

[David Bohner]

I have been listening to the Bigger Pockets Podcast and the term A class, B class, and C class comes up often in respect to property pretty often. I've deduced an A class property is a newer property that meets the current ideal trend for the market and B class is nice property but is not the top of the line or the ideal for the market. Is my assumption accurate and what defines the different classes? And what consideration does an investor need to look at when looking at properties?