At an upper level of any computer architecture, a computer is supposed to have a processor, memory and some I/O components, with one or more quantities of each type. These components are interrelated and connected in a way to achieve the major function of the computer, which is to execute programs. So, there are four key structural elements of any computer. These are:

  • Processor: It controls the processes within the computer and carries out its data processing functions. When there is only one processor available, it is in combination termed as the central processing unit (CPU), which you must be familiar with.
  • Main memory: It stores data and programs within it. This memory is typically volatile and is also called primary memory. This is because when the computer is shut down, the contents that are within the memory gets lost. In contrast, the contents of disk memory are kept hold of even when the computer system is turned off which you call as shutting down of Operating system or computer. Main memory is also termed as real memory.
  • I/O modules: This moves the data within the computer to its peripheral external environment. The external environment supposed to have a variety of devices, including secondary memory devices (e.g., pen drives, CDs, etc.), communications equipment (such as LAN cable), terminals, etc.
  • System bus: It provides communication between processors, main memory, and I/O modules.