Digital Logic, Transistors, and How Computers Think

🔷 The Big Idea: Computers Are Electrical and Logical

On Tuesday, you learned how electricity moves.

On Wednesday, you learned how we manage heat and mechanical stability.

Today you learn how electricity becomes logic. How logic becomes operations. And how operations become computing.

Every program you’ve ever used—games, apps, social media—exists because electrical signals are turned into 1s and 0s, and those 1s and 0s control billions of tiny switches.

🔌 Transistors: The Building Blocks of Everything

What is a Transistor?

A tiny electronic switch that can turn on or off based on electrical signals.

• ON = electricity flows
• OFF = electricity is blocked
• Billions of these fit inside a modern CPU

Why they matter:

• They replace mechanical switches
• They switch extremely fast
• They use very little energy
• They are reliable and tiny

Transistors make it possible for computers to represent binary.