Here's a breakdown:

* Peptide: A short chain of amino acids linked together by peptide bonds.

* Polypeptide: A long chain of amino acids linked together by peptide bonds. It's essentially a larger version of a peptide.

Note: Sometimes the terms "polypeptide" and "protein" are used interchangeably. However, technically, a protein is a polypeptide that has a specific three-dimensional structure and biological function.