Peptidases, also known as proteases or proteinases, are enzymes that break down proteins into smaller peptides or amino acids. They play a crucial role in various biological processes, including digestion, cell signaling, and the regulation of metabolic pathways. By cleaving peptide bonds, peptidases help the body utilize proteins from food and recycle cellular proteins. These enzymes are classified into different categories based on their structure and mechanism of action, such as serine peptidases, cysteine peptidases, and metallopeptidases. Peptidases are found in many organisms, including humans, where they are essential for maintaining overall health and proper functioning of the immune system.