Most general purpose computers are based on von Neumann architecture. This includes using the fetch-decode-execute cycle to process program instructions. Computer performance depends on cache size, clock speed and the number of cores.
In early computer systems, machine instructions were stored on punch cards and data could be stored on another media such as magnetic tape. This kept the instructions and data entirely separate from one another, known as the Harvard architecture. In modern computer systems this can be achieved by using a central processing unit with two separate memory units, one to store machine instructions and another to store data, which are connected by different buses.