The difference is very big, the difference is more than ten times.
The biggest difference between 14 nm and 3 nm is that the transistor density is different, and the difference between the two is more than ten times. Nanometer refers to the gate width in chip manufacturing, and the smaller the gate width, the more silicon transistors per unit area. The transistor density of a 14-nanometer chip is about 20 million per square millimeter, while the transistor density of a 3-nanometer chip is about 250 million per square millimeter, a difference of more than ten times.