Difference between "the very first" and "first"

I have the sentence:

Who wrote the very first dictionary ever?

Is it any different from

Who wrote the first dictionary ever?

I don't get how something could be more first.

It just places greater emphasis on the first instance of whatever it is being a big deal. For that matter, ever in that sentence is used in exactly the same role; "who wrote the first dictionary?" also has the same denotative meaning.

Typically, the "very" will be used to add emphasis (such as in your example), but it can also clarify the scope of the question.

"When did you have your first cup of coffee?" could refer to your first cup of the day, or the first cup in your life. By contrast, "When did you have your very first cup of coffee?" will almost always be interpreted as referring to the first cup of your life.

In this case, very is used as an adverb. It adds emphasis and acts as an intensifier.

Other than that, there is no difference between the two.

The difference is not in the denotation of the question (either will elicit the same answer) but in the affect - which is just as important a component of language, if harder to define and quantify.

Any correct answer to one of them will be a correct answer to the other, and any answer which does not satisfy one will fail to satisfy the other. But the speaker is conveying some emotion, or how they value the information, by the choice of question.

They are not exactly the same, but they are almost the same.

In this specific example, the "first dictionary" could be answered include only objects that called themselves a dictionary, or were called a dictionary.

The extra emphasis in the "very first dictionary ever" would imply you want to include anything that also served as a dictionary, even if it isn't normally called as such.

For example, the "first computer" is often considered to be the ENIAC, because it was the "first general-purpose electronic computer", which is the type of computer we all use nowadays. However, the "very first computer ever" would include adding machines - a mechanical, single-purpose computer.

EDIT: To define what I mean more precisely, the "first foo" generally means the first foo that exists in the modern sense of the word, while the "very first foo ever" includes versions that predate its modern form.