Это абсолютно верно.

In Russian, the verb to be is usually omitted in the present tense.

So where English says:

• This is correct
• That is absolutely true

Russian often just says:

• Это верно
• Это абсолютно верно

If you wanted past or future, a form of быть would appear:

• Это было верно = This was correct
• Это будет верно = This will be correct

Это often means this, that, or sometimes it, depending on context.

In this sentence, it usually refers to:

• a statement someone just made
• an idea
• a fact that is being discussed

So это does not have to point to a physical object. It can point to a whole previous sentence, like English That’s absolutely right.

Верно is the form normally used in this kind of sentence because it works as a predicate: it describes the situation as correct / true / right.

Compare:

• верный ответ = a correct answer
  
  • here верный is a full adjective before a noun
• Ответ верен = The answer is correct
  
  • here верен is a short-form predicate adjective
• Это верно = That is correct / true
  
  • here верно is the neuter short form

So in Это абсолютно верно, верно is not modifying a noun directly. It is the main descriptive part of the sentence.

Because это is grammatically treated as neuter singular, so the predicate appears in the neuter form too:

• Это верно
• Это понятно
• Это ясно

This is very common in Russian. Even when это refers to a whole idea rather than a literal neuter noun, Russian still uses the neuter form.

They are close, but not always identical.

In many contexts, both can mean correct / right:

• Это верно
• Это правильно

But there is a slight nuance:

• верно often means true, accurate, factually correct
• правильно often means correct, proper, done the right way

Examples:

• Это верно = That is true / correct
• Ты правильно написал слово = You wrote the word correctly

In your sentence, верно sounds very natural because it is confirming that something is true or correct.

Абсолютно is an adverb meaning absolutely, completely, or totally.

It strengthens верно:

• Это верно = That is correct
• Это абсолютно верно = That is absolutely correct

It works much like English absolutely in That’s absolutely right.

Yes, Russian word order is flexible, but the neutral order here is:

• Это абсолютно верно

You may also hear:

• Абсолютно верно — very common, especially as a reply
• Это верно — less emphatic
• Это совершенно верно — совершенно is another common intensifier, like quite / absolutely

The original version sounds natural and neutral.
If you drop это and just say Абсолютно верно, it sounds like a direct response: Absolutely right.

The stress is:

• Э́то
• абсолю́тно
• ве́рно

A simple pronunciation guide:

• Э́то ≈ EH-tuh
• абсолю́тно ≈ ab-sa-LYOOT-na
• ве́рно ≈ VYER-na

A rough full pronunciation:

EH-tuh ab-sa-LYOOT-na VYER-na

The unstressed о in Russian is usually reduced in speech, so the last -о in верно does not sound like a strong English oh.

It is natural in both speech and writing. It is not overly formal.

You could use it:

• in conversation
• in class
• in writing
• in a discussion
• in response to someone’s statement

It sounds a bit more polished than a very casual Да, точно or Да, правильно, but it is still completely normal.

Yes. It is very commonly used to agree with what someone said.

For example:

• Person A says something
• Person B replies: Это абсолютно верно.

In English, depending on context, this could sound like:

• That’s absolutely right.
• That’s absolutely true.
• That is completely correct.

Russian often uses это to refer back to the whole previous statement.

Yes. Совершенно is another very common intensifier.

So these are all natural:

• Это верно = That is correct
• Это абсолютно верно = That is absolutely correct
• Это совершенно верно = That is absolutely / completely correct

Both абсолютно and совершенно work well here.
Совершенно верно is especially common as a spoken confirmation.

No. Это абсолютно верно. is a simple sentence, so no comma is needed.

You just write it as:

Это абсолютно верно.

If it were part of a longer sentence, punctuation would depend on the larger structure, not on this phrase itself.