Verification : It is Process Oriented.It is done by QA People.
 and its to meet the product specification.It is done at the
 application developing stage.

Validation: It is Product Oriented.It is done by QC People
and its to meet the user and customer Req.It is done by
testing phase.

Verification is been done with the requirements in each
phase of the project life cycle. 
validation is been done to validate the project execution in
the user environment after implementing the project.

Verification:Are we building the product right?
Validation:Are we building the right product?

A perfect software product is built when every step is taken
with full consideration that ‘A right product is developed
in a right manner’. ‘Software Verification & Validation’ is
one such model, which helps the system designers and test
engineers to confirm that a right product is build right way
throughout the development process and improve the quality
of the software product.

‘Verification & Validation Model’ makes it sure that,
certain rules are followed at the time of development of a
software product and also makes it sure that the product
that is developed fulfills the required specifications. This
reduces the risk associated with any software project up to
certain level by helping in detection and correction of
errors and mistakes, which are unknowingly done during the
development process.

What is Verification?
The standard definition of Verification goes like this: "Are
we building the product RIGHT?" i.e. Verification is a
process that makes it sure that the software product is
developed the right way. The software should confirm to its
predefined specifications, as the product development goes
through different stages, an analysis is done to ensure that
all required specifications are met.

Methods and techniques used in the Verification and
Validation shall be designed carefully, the planning of
which starts right from the beginning of the development
process. The Verification part of ‘Verification and
Validation Model’ comes before Validation, which
incorporates Software inspections, reviews, audits,
walkthroughs, buddy checks etc. in each phase of
verification (every phase of Verification is a phase of the
Testing Life Cycle)

During the Verification, the work product (the ready part of
the Software being developed and various documentations) is
reviewed/examined personally by one ore more persons in
order to find and point out the defects in it. This process
helps in prevention of potential bugs, which may cause in
failure of the project.

Few terms involved in Verification:
Inspection:
Inspection involves a team of about 3-6 people, led by a
leader, which formally reviews the documents and work
product during various phases of the product development
life cycle. The work product and related documents are
presented in front of the inspection team, the member of
which carry different interpretations of the presentation.
The bugs that are detected during the inspection are
communicated to the next level in order to take care of them.

Walkthroughs:
Walkthrough can be considered same as inspection without
formal preparation (of any presentation or documentations).
During the walkthrough meeting, the presenter/author
introduces the material to all the participants in order to
make them familiar with it. Even when the walkthroughs can
help in finding potential bugs, they are used for knowledge
sharing or communication purpose.

Buddy Checks:
This is the simplest type of review activity used to find
out bugs in a work product during the verification. In buddy
check, one person goes through the documents prepared by
another person in order to find out if that person has made
mistake(s) i.e. to find out bugs which the author couldn’t
find previously.

The activities involved in Verification process are:
Requirement Specification verification, Functional design
verification, internal/system design verification and code
verification (these phases can also subdivided further).
Each activity makes it sure that the product is developed
right way and every requirement, every specification, design
code etc. is verified!

What is Validation?
Validation is a process of finding out if the product being
built is right?
i.e. whatever the software product is being developed, it
should do what the user expects it to do. The software
product should functionally do what it is supposed to, it
should satisfy all the functional requirements set by the
user. Validation is done during or at the end of the
development process in order to determine whether the
product satisfies specified requirements.

Validation and Verification processes go hand in hand, but
visibly Validation process starts after Verification process
ends (after coding of the product ends). Each Verification
activity (such as Requirement Specification Verification,
Functional design Verification etc.) has its corresponding
Validation activity (such as Functional Validation/Testing,
Code Validation/Testing, System/Integration Validation etc.).

All types of testing methods are basically carried out
during the Validation process. Test plan, test suits and
test cases are developed, which are used during the various
phases of Validation process. The phases involved in
Validation process are: Code Validation/Testing, Integration
Validation/Integration Testing, Functional
Validation/Functional Testing, and System/User Acceptance
Testing/Validation.

Terms used in Validation process:
Code Validation/Testing:
Developers as well as testers do the code validation. Unit
Code Validation or Unit Testing is a type of testing, which
the developers conduct in order to find out any bug in the
code unit/module developed by them. Code testing other than
Unit Testing can be done by testers or developers.

Integration Validation/Testing:
Integration testing is carried out in order to find out if
different (two or more) units/modules co-ordinate properly.
This test helps in finding out if there is any defect in the
interface between different modules.

Functional Validation/Testing:
This type of testing is carried out in order to find if the
system meets the functional requirements. In this type of
testing, the system is validated for its functional
behavior. Functional testing does not deal with internal
coding of the project, in stead, it checks if the system
behaves as per the expectations.

User Acceptance Testing or System Validation:
In this type of testing, the developed product is handed
over to the user/paid testers in order to test it in real
time scenario. The product is validated to find out if it
works according to the system specifications and satisfies
all the user requirements. As the user/paid testers use the
software, it may happen that bugs that are yet undiscovered,
come up, which are communicated to the developers to be
fixed. This helps in improvement of the final product.

Hi, 
   Shailaja you rock. The best answer i ever seen for these 
two terms.

Why isn't load testing included ?????