Target – Cycles gems, metals and Barrel
3D models are viewed on 2D screens. 2D screens consist of a grid of thousands of colored dots called pixels. The process of converting 3D data into 2D images is called rendering.
Real-time rendering is needed for when you are working on your models and playing games.
Non real-time rendering is when you want the best results including objects being lit by light bouncing off other objects in a scene.
Blender Internal Render, Cycles Render and Blender Game
Blender internal render is the original render and for continuity has not changed much over the years.
Over time techniques for creating realistic materials have been developing. Rather than changing the material system in Blender, an alternative material system and render engine is now offered and it is called ‘Cycles’.
An alternative would not have been added if it did not offer reasonably substantial advantages in realism, speed and ease of use.
For real-time rendering in the game engine, the best option is OpenGL, which is open source and cross platform.