How Computers Work

We use computers on a regular basis for nearly everything. Whether its laptops, smartphones, or tablets, all computers work in fundamentally the same way. In this section, we’ll lay out the physical components that make a computer work. We’ll talk about how various hardware components like hard drives, CPUs, RAM, ports, and more interact with software to create the experience we are familiar with today.

The resources in this section come from a course called Computer Science E-1a, Understanding Technology, offered at Harvard’s Extension School.

• Lecture

  • Watch on Youtube
  • Watch on the CS50 Video Player
  • Download Lecture
  • Lecture Notes

• Notes

  • How Computers Work

• Supplementary Resources

  • Khan Academy on CPU, Memory, Input & Output
  • Khan Academy on Hardware and Software

• Thought Questions

  • How does having separate physical components affect how hardware is developed?
  • To what extent are different components dependent upon how the other components are built?
  • Are there different layers of hardware? What makes up these layers, and how do they interact?
  • What happens to hardware that becomes outdated?