Difference between "validation" and "verification"

What is the difference between validation and verification? When looking them up on Wiktionary they seem to mean mostly the same thing, but is there a difference?

For example, would I be correct in saying that

• Checking that the format of an email address is valid, would be validation?
• The process of sending an email to an email address to have a user click on a link to make sure the email is in use and correct, would be verification?

Or could I have used both words in both cases?

Solution 1:

Note - In systems:

Validate (to check the aliveness, legal status, existence of data). To check the ‘validity’ of data - does it comply with the ‘legal’ or required format of the system.

Verify (to check the truth) - to check whether something is true. To verify that a user exists, verify that an account is current, to ‘check the truth of’ ... anything.

Validation - Validate: means ‘having force in law, legally binding’, from the Latin - validus -"strong, effective, powerful, active". Validation is ‘the process of checking that something is legally or currently active.’

Examples:

• ‘Sorry sir. Your passport is no longer valid. It’s out of date’.
• ‘Sorry, your gift voucher is no longer valid, it expired’.

• ‘Sorry madam - our validation has shown that this cheque isn’t real - it’s a fake’.

• When our system tries to validate this email address we see it is invalid, it uses the wrong format

• This email address is invalid - the user doesn’t exist

https://www.etymonline.com/word/valid

Verification - Verify - is from the Latin ‘verus’ or truth. It means ‘to check the truth’ or - check if (something is) true. Verification is ‘the process of checking whether something is true’.

Examples:

• We have verified the image on your passport and confirm that it is your true image.
• We have checked your blood and can verify (note - it means ‘state as true’) that you do not have anaemia.
• Our verification of your order is complete and we can confirm that the box we sent you contains 15 white hats and 5 green.
• We cannot verify this email user on our server. They don’t seem to exist.

https://www.etymonline.com/word/verify

Solution 2:

I think the subtle difference would be in that "verification is validation by empirical means".

empirical: Based on, concerned with, or verifiable by observation or experience rather than theory or pure logic.

Taking your example, checking the format of an email address is done by logic, to see if you have <something>@<something>.<xxx> format. But, you cannot logically tell by looking at the string that it is a genuine email address.

Solution 3:

Validate comes from the Latin validus, meaning strong.

Verify comes from veritus, meaning true.

We often say that an argument founded on strong principles is valid. For instance:

"I cannot see the stars. I have no way of knowing if they're still there. For all I know, they might have disappeared, and scientists around the world are lying when they say they're there."

"Your argument is valid, but I'm pretty sure scientists have better things to do."

On the other hand, we could say,

Scientists today verified that the stars did in fact disappear during daylight, when astronauts aboard the shuttle "Scepticism" travelled above the atmosphere for the first time and found that no stars above the daylight side were visible.

The biggest difference is in the hypothesis. A valid hypothesis is one which appears to have supporting evidence, or which has not been disproven*. A verified hypothesis is one which has been proven (in this case, the anti-hypothesis).

Let's say that your hypothesis is that the user has entered their email address correctly. The address is valid if it's well-formed, or if you can send an email to it - it exists - but only verified as the user's address once the link sent in the email is clicked.

Or perhaps your hypothesis is that entries in a form are correct. It might be valid if all mandatory fields are filled, but only verified once the business rules associated with the different fields have been checked too.

Because verification necessarily involves validation, there may be some flexibility about what you define as valid. The purpose of validation is usually to provide quick feedback about what might be wrong, whereas the purpose of verification is to make sure it's right.

(*Can anyone verify that "disproven" is a word? Please validate my assumption.)