Internet Basics

Computers have revolutionized the way people around the world communicate. But how do computers communicate, or transfer information, to each other?

In this section, we’ll discuss what the Internet is and how information travels on networks. We’ll see how computer networks operate very similarly to a traditional mail system, complete with addresses, packages, rules, and routes.

• Lecture (Part 0)

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

• Lecture (Part 1)

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

• Short

  • Internet Primer

• Notes

  • Internet Basics

• Supplementary Resources

  • Mike Kujawski on Global internet statistics for 2018
  • Bill McCabe on Quick History of the Internet of Things
  • Blake Snow on What Would a World Without Internet Look Like?
  • FrippeMax on Warriors of the Net

• Thought Questions

  • How fundamental is the Internet to your everyday life? Could you live without it? What about on a global scale? To what extent do we rely on the Internet?
  • Imagine that your computer has just lost its connection to the Internet. What are the places you should look to find the problem?
  • What are the advantages of using an Ethernet cable over Wi-Fi to connect a device to the Internet? (Hint: Consider speed, reliability, and practicality.)
  • Given the many different components that comprise an internet connection, how do we ensure all of them work together properly? (Hint: What do we mean by “protocols” and why do they matter? What “protocols” do you use in your everyday life?)