GPU (Graphic Processing Unit)

A GPU  is a specialized microprocessor that offloads and accelerates 3D or 2D graphics rendering from the general purpose CPU.

Need for GPU

As 3D becomes more pervasive in our lives, the need for faster processing speeds increases. With the advent of the GPU, computationally intensive transform and lighting calculations were offloaded from the CPU onto the GPU—allowing for faster graphics processing speeds.

the above picture clearly shows the effect of GPU so you can imagine how important it is now adays.