Describe the two alternatives for specifying structural constraints on relationship kinds?

Relationship kinds have certain constraints in which limit the possible combination of entities that might participate in relationship. An example of a constraint is in which if we have the entities Doctor and Patient, the organization might have a rule that a patient cannot be seen through more than one doctor. This constraint needs to be elaborates in the schema. There are two major kinds of structural relationship constraints on: cardinality ratio, and participation.