Smartphones, computers, game consoles—there are many “computers” around us. In this lesson, we will gently explore what kind of work computers do and how the Internet connects us to the world.
What Does a Computer Do?
Simply put, a computer is a machine that repeatedly performs the following tasks: “① receive something → ② think (calculate) → ③ produce an answer.” For example, when you enter “3＋5” into a calculator, the computer receives it (①), performs the calculation inside (②), and displays “8” on the screen (③). When you move a game controller (①), calculations are performed in the game (②), and the character moves on the screen (③). Smartphone apps work the same way when they respond as soon as you tap them.
What Is the Internet?
The Internet is a large “connection” that links many computers around the world with cables and radio waves so that they can exchange information. This connection is what allows a photo sent from your smartphone to reach a friend’s smartphone far away. One computer is not directly connected to every computer in the world. Instead, information is delivered by passing through many machines along the way, like a relay race.
What Is Wi-Fi?
Wi-Fi is a system that connects to the Internet using radio waves instead of cables. A machine called a “router” in homes, schools, and cafés sends out radio waves, and smartphones and computers can connect to the Internet within the range of those waves. Wi-Fi is often protected by a “password” so that strangers cannot use it without permission.
Computers Are Everywhere
In fact, “computers” are not limited to PCs and smartphones. Microwaves, washing machines, traffic lights, and automatic ticket gates also contain small computers and operate using the same “receive → think → produce an answer” process. Our lives are supported by many small computers.
- A computer’s work has three steps: “receive → think (calculate) → produce an answer.”
- The Internet is a large system that connects computers around the world.
- Wi-Fi is a system that connects to the Internet using radio waves without cables.
- A Wi-Fi password is a key that prevents strangers from using it without permission.
- Everyday machines such as microwaves and traffic lights also contain computers.
Practice Problems
- Using the calculator example “3＋5＝8,” explain the three steps a computer follows when doing its work.
- Explain in your own words what the Internet is.
- State why home Wi-Fi is protected by a password.
Answers and Explanations
- Answer: The three steps are: ① receive the numbers “3＋5,” ② calculate the addition inside the computer, and ③ display the answer “8” on the screen.
Explanation: The answer is correct if the three steps “receive → think → produce an answer” are written in the proper order. - Answer: A large system in which many computers around the world are connected by cables or radio waves and can exchange information with one another.
Explanation: It is sufficient to state that many computers are connected. It is not necessary to memorize difficult terminology. - Answer: To prevent passersby and others who do not know the password from using the Internet without permission.
Explanation: The answer is sufficient if it explains that radio waves can pass through walls and reach outside, so anyone could use the connection without a key (password).