هذا نوع مختلف.

Because Arabic often leaves out the present-tense verb to be.

So in English you say This is a different type, but in Modern Standard Arabic you normally just say:

هذا نوع مختلف

This is a very common pattern in nominal sentences.
The structure is basically:

هذا = this
نوع مختلف = a different type

If you wanted was, will be, and so on, Arabic would usually use an actual verb.

It can function as a full sentence.

In this sentence:

هذا is the subject/topic
نوع مختلف is the predicate/comment

So the whole sentence means something like:

This is a different kind/type.

Even though it is short, it is grammatically complete in Arabic.

هذا is the masculine singular form of this.
هذه is the feminine singular form.

Here, the sentence uses the masculine singular pattern, and نوع is a masculine noun in Arabic. So هذا is the expected form.

A learner coming from English often forgets that Arabic nouns have grammatical gender, even when English nouns do not.

نوع means type, kind, or sort.

So:

نوع مختلف = a different type / a different kind

It is a very common word in both formal and everyday Arabic. You will also often see it in longer expressions like:

نوع من... = a kind of...

For example:

هذا نوع من الطعام = This is a type of food

Because Arabic adjectives normally come after the noun they describe.

So:

نوع مختلف
literally = type different

but naturally means:

a different type

This is the normal adjective position in Arabic. English usually puts adjectives before the noun, but Arabic usually puts them after.

Because the meaning is a different type, not the different type.

In Arabic, adjectives usually match the noun in definiteness. So if the noun is indefinite, the adjective is also indefinite:

نوع مختلف = a different type

If you made them definite, the meaning would change. Compare:

هذا نوع مختلف = This is a different type
هذا النوع مختلف = This type is different

That contrast is very important.

In fully vocalized MSA, this would usually be:

هٰذا نَوْعٌ مُخْتَلِفٌ

Both نوعٌ and مختلفٌ are in the nominative here.

Why?

Because نوع مختلف is the predicate of the sentence, and مختلف is an adjective describing نوع, so it matches it.

In normal unvocalized writing, those endings are usually not written. In pause, many speakers also do not pronounce the final -un sound clearly.

So you may hear something closer to:

hādhā nawʿ mukhtalif

instead of the full citation-style:

hādhā nawʿun mukhtalifun

Here, مختلف is functioning as an adjective meaning different.

Historically and morphologically, it comes from the verb اختلف meaning to differ or to be different. So مختلف is related to the idea of something that differs.

For a learner, the important point is:

مختلف = different

And in this sentence it agrees with نوع:

• masculine
• singular
• indefinite

A careful pronunciation is:

hādhā nawʿun mukhtalifun

In pause, very commonly:

hādhā nawʿ mukhtalif

A few pronunciation notes:

• هذا = hādhā
  • the dh sounds like the th in this
• نوع = nawʿ
  • the final ʿ is the Arabic letter ع
• مختلف = mukhtalif
  • kh is like the sound in Scottish loch or German Bach

Yes, but the meaning changes.

هذا مختلف = This is different
هذا نوع مختلف = This is a different type/kind

So adding نوع makes the idea more specific. It is not just saying that something is different in general; it says that it belongs to a different category or kind.