If you still don’t know about what mini, micro and nano are in matter of value you can look for them in the table at the end of this article. The are usually used to measure distance and weight, but not only that, and lately they became something very common for the computer technology even when the people using these terms did not understand their real meaning. Some speak about the processors having the distance between their transistors measured in nano or about micro devices and I wonder if they really understand what they are talking about.
Historical, the first computers were so big they only fit in entire rooms and there were allocated sections of buildings for storing them. They worked with card and it was not easy to translate the human language to the holes in the cards and back to something readable. The first PC (personal computers) had the size of the current laptops (or a little bigger), but the current smartphones have a better processing power than an entire network of old PC. The transition from that computers to the current laptops, tablets and other devices was made possible through the progess of technology that allows the miniaturization of the circuits.