Peptide bonding
Amino acids join together by what is called a peptide bond. During translation many peptide bonds are formed. These are formed on the surface of the ribosome. The product is called a polypeptide because it is made of many amino acids joined by many (poly) peptide bonds.
R1 and R2 are two different R groups. Also remember that the carboxyl group on the left amino acid joins with the amine group of the right amino acid. Water is lost in a condensation reaction.