Peptides are organic chemical molecules. They are polymers made from linking amino acids together in a certain order. The link between one amino acid residue and the next is known as an amide bond or a peptide bond.
Linking peptides together gives proteins, which are polypeptides.

Gly-Gly, or Glycylglycine is (a dipeptide and also) the simplest peptide; It is the dipeptide of Glycine.