A Candidate Instance can be validated against a Type. The Validation action takes a Candidate Instance and a Type (typically, a set of Schema Documents and the name of a Type defined in one of them). It results in a boolean that describes whether the Candidate Instance is valid against the Type given its definition in the set of Schema Documents. If the Candidate Instance is not valid, a list of errors is provided that describes how the Candidate Instance is not conforming to the Type.