The Linac Coherent Light Source (LCLS) is a powerful X-ray free-electron laser located at the SLAC National Accelerator Laboratory in California. It generates extremely bright and short pulses of X-rays, allowing scientists to study materials and biological samples at the atomic level. LCLS uses a linear accelerator to produce high-energy electrons, which are then converted into X-ray light through a process called self-amplified spontaneous emission. This technology enables researchers to capture rapid processes, such as chemical reactions and molecular dynamics, providing valuable insights across various fields, including physics, chemistry, and biology.