Copyright: blender cycles
Cycles is a physically based render engine available in Blender that is capable of creating photorealistic images and animations. Unlike EEVEE which is a raster engine, Cycles renders images using path tracing where light rays are simulated bouncing throughout a scene. While Cycles can create highly realistic photos, it takes much longer to render an image compared to methods like rasterisation due to the amount of light rays that need to be simulated.