Polymerase Chain Reaction (PCR) is a laboratory technique used to amplify specific segments of DNA. It allows scientists to create millions of copies of a particular DNA sequence, making it easier to study and analyze. PCR involves repeated cycles of heating and cooling, which separate the DNA strands and enable the addition of primers and enzymes to replicate the target DNA. This method is widely used in various fields, including genetics, forensic science, and medical diagnostics. PCR can help identify genetic disorders, detect pathogens, and analyze genetic material from crime scenes, making it a crucial tool in modern biology and medicine.