What Is The Difference Between `verification` And `validation`?

In simple words, Verification is quality control in which we only take corrective actions and Verification is quality assurance which involves preventive actions. Software companies combine both verification and validation in their software quality assurance departments to produce high quality software.
Software Quality Assurance is an essential part of Software Development Life Cycle and Software Testing comes under Software Quality Assurance. Validation and Verification are part of Software Quality Assurance and Software Testing.
To understand the basic concept of Verification and Validation, let's discuss them separately.
Verification is a process of ensuring that every product is designed according to the user requirements. Reviews and meetings are conducted to evaluate different documents. These include requirements, specifications, plans and code. Evaluation of all these documents is done via checklists, walkthroughs and inspections. After completion of verification we move one step further and start validation.
Validation involves the actual testing where we check the program design to see if it is according to the intended design. Validation is performed both by software developers and software testers. Unit testing comes under validation and it is performed by Software developers in order to check that their code is working correctly. Alpha and beta testing also comes under validation.

Verification is derived from verify and validation is from validate.

According to Answers.com, the definition of Verify is:

1. To prove the truth of by presentation of evidence or testimony;
substantiate. 2. To determine or test the truth or accuracy of, as by
comparison, investigation, or reference: Experiments that verified the
hypothesis. See synonyms at confirm. 3. Law. 1. To affirm formally or
under oath. 2. To append a verification to (a pleading); conclude with
a verification.

Verification is check the everything documents of process
validation is check the date and time

I don't know I think validation is date and time the other is everything documents of process

Validation and verification are very similar, depending on their use. Infact, they are often listed as synonyms for one another.

Hope this helps!

Verification is:
1. The act of verifying.  
2. The state of being verified.  
3. Evidence that establishes or confirms the accuracy or truth of something: We could find no verification for his fantastic claims.  
4. A formal assertion of the truth of something, as by oath or affidavit.  
5. The process of research, examination, etc., required to prove or establish authenticity or validity.  
6. Law. A short confirmatory affidavit at the end of a pleading or petition.

Validation is:
1. To make valid; substantiate; confirm: Time validated our suspicions.  
2. To give legal force to; legalize.  
3. To give official sanction, confirmation, or approval to, as elected officials, election procedures, documents, etc.: To validate a passport.

Found at: dictionary.reference.com and dictionary.reference.com

Verification typically involves reviews and meetings. To ensure documents, plans.
But after verification only validation takes place. Validation is nothing but actual testing.