Cycles is a rendering engine that first appeared in Blender version 2.61 (December 2011). It is available as an add-on to the program alongside the new built-in EEVEE render. Cycles creates an image using ray tracing with an emphasis on interactivity and ease of use. For materials, a system of nodes is used, with which you can create photorealistic materials of any complexity. The big advantages of the engine are the ability to quickly view the result directly in the 3D view window, as well as rendering using a graphics card (GPU). The Cycles rendering engine has 80 + nodes for creating materials. Remembering them all and knowing what everyone is doing is problematic enough if you don't create materials with it on a daily basis. But with the help of this book, it will not be difficult for you to find out what each node (and not only nodes) is doing, and at any time refresh your memory of the previously acquired knowledge.