  Gravitational lensing has been identified as a powerful tool to address
fundamental problems in astrophysics at different scales, ranging from
exoplanet identification to dark energy and dark matter characterization in
cosmology. Image simulations have played a fundamental role in the realization
of the full potential of gravitational lensing by providing a means to address
needs such as systematic error characterization, pipeline testing, calibration
analyses, code validation, and model development. We present a general overview
of the generation and applications of image simulations in strong and weak
gravitational lensing
