Peptide synthesis is the controlled, stepwise formation of amide bonds between amino acids to produce a defined linear or cyclic peptide sequence. In organic chemistry synthesis methods the concept encompasses both chemical assembly and, by extension, nonribosomal enzymatic assembly, but it is bounded by the production of a peptide as the target rather than of a folded protein by ribosomal translation. Solid-phase peptide synthesis anchors the C-terminal residue to an insoluble resin and adds N-protected amino acids iteratively, so that excess reagents are removed by filtration after each coupling ^[1]. The 9-fluorenylmethoxycarbonyl (Fmoc) and tert-butoxycarbonyl (Boc) protecting-group schemes define two principal chemical strategies; Fmoc chemistry uses base-labile Nα protection, whereas Boc chemistry uses acid-labile Nα protection and often employs in situ neutralization to improve the assembly of difficult sequences ^[2][3]. Nonribosomal peptide synthetases construct peptides on modular protein assembly lines that activate, thiolate, and condense amino acids without a messenger-RNA template ^[4]. The concept is distinguished from protein expression by the chemical or modular-enzymatic rather than ribosomal mechanism, and from simple amide-bond formation by the requirement for sequence control across multiple residues.