These buttons are programmed intelligently based on thousands of experiments to achieve the best cooking results.
Take the “Rice” button as example. During rice cooking Instant Pot estimates the amount of rice and water by measuring the pre-heating time. The pressure cooking duration is then varied based on this measurement. Detailed considerations are taken during each rice cooking stage of soaking, blanching, steaming and braising. See Pete Vegas’ “Rice 101″ to learn more about the science of cooking rice.
Each function button can further be refined to vary food taste in the range of “rare”, “normal” and “well-done”.