Explain the proper use of the comma to set apart nonessential elements within a sentence

A nonessential element, also referred to as nonrestrictive element, is a word, phrase or clause that is not essential to the meaning of the sentence. When a nonessential clause is removed from the sentence, the sentence still makes sense without it; it is unrestricted, or not essential.

Nonessential elements are always offset with commas. The commas dictate a pause when you are reading the sentence or speaking it out loud. If the word, phrase or clause is easily removed from the sentence or moved to another spot within the sentence, the clause is set off with commas on each side. Likewise, if the element interrupts the flow of the sentence, offsetting commas are used.

Example:

-The information, however, was inaccurate.

-The information was inaccurate, however.

-The information was inaccurate.

"However" is a nonessential word because it interrupts the flow of the sentence, requiring offsetting commas. It is also moved without changing the meaning of the sentence.