How to differentiate appositive clause from a relative clause?

Can an appositive clause be relative clause in terms of terminology when they are used as in the following examples :

Jupiter, the largest planet in the solar system, has a prominent red spot.

Jupiter, which is the largest planet in the solar system, has a prominent red spot.

" the largest planet in the solar system" seems like a non-defining relative clause (aka non-restrictive relative clause). An appositive clause, like relative clause, can also be restrictive or non-restrictive.

Other examples could be :

My best friend , a good tennis player in his own right, won many prizes.

My best friend, who is a good tennis player in his own right, won many prizes.

My brother, a teacher in Boston, is moving to New Jersey.

My brother, who is a teacher in Boston, is moving to New Jersey.

Compare:

Jupiter, which revolves around the Sun once every 11.86 Earth years, has a prominent red spot.

And

Jupiter, which is the largest planet in the solar system, has a prominent red spot.

The former, "which revolves around the Sun …", is non-identifying adjective clause which doesn’t give another name to the noun "Jupiter" that modifies, so it cannot be reduced.

But the latter, "which is the largest planet …", gives another name to Jupiter.

Jupiter= the largest planet in the solar system.

An appositive is a noun or noun phrase that renames another noun right beside it.

So, the reduction creates an appositive clause.