Nanotechnology involves manipulating matter at the atomic scale between 1 to 100 nanometers. It has applications in quantum computing which operates at the quantum level using quantum bits that can represent both 1s and 0s through superposition and entanglement. While a quantum computer could solve certain problems much faster than classical computers by processing vast amounts of calculations simultaneously, they still face limitations such as unpredictability, difficulty retrieving data, and requiring total isolation from the environment to maintain fragile quantum states.