• Noun: a collection of things sharing a common attribute; example: "there are two classes of detergents"
• Noun: a general concept that marks divisions or coordinations in a conceptual scheme
Your memorabilia becomes more significant. It does put you in a different category.
I'm not a minister, I'm not a philosopher, I'm not a politician, I'm in another category.
In America, the professor talks to the mechanic. They are in the same category.