Optical trapping, also known as optical tweezers, is a technique in physics and biology that uses highly focused laser beams to trap and manipulate small particles, such as cells or nanoparticles. The technique works by exploiting the radiation pressure of the laser light, which creates a gradient force that attracts particles towards the center of the laser beam. This allows researchers to manipulate and study the behavior of individual particles in a controlled environment. Optical trapping has a wide range of applications in various fields, including biology, physics, and chemistry, and has been instrumental in studying the mechanical properties of cells, microrheology, and single molecule biophysics.