Abstract: The quest to get sharper images of the universe with telescopes on ground where larger telescopes can be installed than those which we can send to space. has led to the development of adaptive optics. The adaptive optics aims to correct for the variations induced by atmospheric turbulence in the incoming optical wavefronts from the objects in the sky in real time on very fast time scales (10-1000 Hz). This necessitates the use of technologies such as wavefront sensors, advanced detectors, fast actuators, laser system controls, deformable mirrors etc. These technologies have been spurred by the requirements of the military, and lasers for controlled thermonuclear fusion and also find uses in ophthalmology. I will describe the basics of the requirements and principles used for adaptive optics and some technologies in use so far.