What is the difference between sandy bridge and ivy bridge processors

Transistor is key component inside processor, which has a physical size. In Sandy Bridge, the transistor size is 32 nano meter (also called 32nm technology). These are called Intel 2nd Generation Processors. There are multiple i3, i5, and i7 Sandy Bridge models.

Under Ivy Bridge, Intel has decreased the transistor size to 22 nano meter. Its mean, more components can be embedded inside same size processor chip, so more processing power can be introduced inside same size physical chip. i3, i5 and i7 with Ivy Bridge type processors are called Intel 3rd Generation Processors.

In Ivy Bridge, Intel has also introduced a new transistor named 3D / Tri-Gate.