cor·re·spondence

– verb
1. to be in agreement or conformity.
2. to be similar or analogous; be equivalent in function, position, amount, etc.

re·la·tion

– noun
1. an existing connection; a significant association between or among things: the relation between cause and effect.
2. the mode or kind of connection between one person and another, between an individual and God, etc.
3. the act of relating, narrating, or telling; narration.
4. a principle whereby effect is given to an act done at one time as if it had been done at a previous time.
5. a property that associates two quantities in a definite order, as equality or inequality.
6. with reference to; concerning.