I am confused on how to understand nouns that in -logy. For instance: "I studied metereology in college." My confusion lies in that these are common nouns. But they seem to refer to a single instance of an object. That would be more like a proper noun, where the noun/name refers to a single, specific object. I guess it hinges at least somewhat on whether the "meteorlogy" that Alice studied is the same as the "meteorology" that Bob studied?
So are these common nouns? Proper nouns? Some kind of third class I am not thinking of? What is the significance of using these nouns in countable versus uncountable forms?