Restrictive
that I baked today
at the top of the stair
Non Restrictive
a talented painter
who is very excited
Explanation:
Restrictive clauses or phrases are those that modify or transform the meaning of the noun that precedes them tangibly and that are such that without the noun present would make no sense with the sentence. They are usually used without any sort of punctuation.
Non restrictive clauses describe the noun they are preceded by but do not tangibly transform it but only add to the overall description of the said noun. Thus, they are used with commas as in the above case.
