How to determine type of neighborhood

[Kyle Scholnick]

What is the general criteria people are using to define a type of neighborhood? I get the idea that A properties are in nice areas and D properties are in not nice areas.....but is anything else determined just by the neighborhood classification?

If you have a really old house, but if its in a nice area, is it still an A?

Does the condition of the home matter or is it just the actual neighborhood?

How do you even determine what is a nice area and what isn't and therefore assign a classification to it if you are looking outside your local market and are unsure?