While rendering objects, OpenGL makes use of a sequence of steps and this sequence of steps is known as rendering pipeline. Firstly, the rendering pipeline prepares the vertex array data and then renders it. A vertex shader acts upon each data and then the processed is turned into an output vertex. Now, these outputs are shifted to different locations. Primitive assembly is made. Now, the scan conversion and primitive parameter interpolation generate a number of fragments. Now, the fragment shader processes each fragment and numbers of outputs are generated. Various tests are conducted in the per-sample processing and hence the final output is obtained.