Verification is the process of determining if a system meets
the conditions set forth at the beginning, or during
previous activities of the software development life cycle,
correctly. These conditions are set forth in software
requirements, which are usually formally documented. The
standard for software requirements documentation is
ANSI/IEEE Standard 830. Verification typically involves
reviews and meetings to evaluate
documents,plans,code,requirements and specifications. This
can be done with checklists, issues lists, walkthroughs, and
inspection meetings.

Validation is the process of evaluating a system to
determine whether it satisfies the specified requirements
and meets customer needs. Validation typically involves
actual testing and takes place after verifications are completed