Verification takes place before validation, and not vice versa.
Verification evaluates documents, plans, code, requirements, and specifications. Validation, on the other hand, evaluates the product itself.
The inputs of verification are checklists, issues lists, walkthroughs and inspection meetings, reviews and meetings. The input of validation, on the other hand, is the actual testing of an actual product.
The output of verification is a nearly perfect set of documents, plans, specifications, and requirements document. The output of validation, on the other hand, is a nearly perfect, actual product.