Commas- Around non-essential words and phrases

A non-essential clause can be removed from a sentence without affecting its grammar.
If information between commas is removed, the sentence still makes sense but may have a different meaning.
Non-essential clauses are always surrounded by commas.
Example of incorrect use: “Steve who is sixty five, runs three miles every day.”
Example of correct use: “Steve, who is sixty five, runs three miles every day.”