What type of punctuation is necessary to set apart nonessential appositive phrases?

commas, dashes, or parentheses

Nonessential appositive phrases can be separated from the rest of a sentence in three ways-with commas, with dashes, or with parentheses. Let’s look at example sentences that essentially mean the same thing:

The best pet in the world, a dog, will always be known as "man’s best friend."

The best pet in the world-a dog-will always be known as "man’s best friend."

The best pet in the world (a dog) will always be known as "man’s best friend."