What is the difference between verification and validation?

Verification assesses whether specifications claimed by the manufacturer are met, and is  applied to equipment, kits, instruments, and reagents. Examples might be to verify a manufacturer's claim that an automated instrument for ABO grouping, Rh typing, and antibody screening can process 40 sample per hour; that a container for shipping red cells can maintain a specific temperature range (e.g., 1-10o C) for a specified number of hours, etc.

Validation assesses whether a process consistently produces an output (result or product) that meets a laboratory's predetermined specifications. The first verification example above could be part of an overall validation to show that the automated instrument produces acceptable results for ABO and Rh typing, and antibody detection in the user's lab compared to the method currently in use.