Beyond numbers and text, programs often need to represent simple "yes" or "no" states, like whether a light switch is on or off.

Swift has a specific data type for this kind of information.

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Can you think of a situation where you only need a true/false answer?

This data type is called a Boolean, named after George Boole. In Swift code, it's shortened to Bool.

A Boolean variable can only hold one of two possible values: true or false.

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Why do you think these specific words are used?

It's crucial to remember that true and false must be lowercase in Swift. True or False (capitalized) won't work.

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How do you think is different from storing the word "true" as a string?

Booleans are fundamental for decision-making in code. We often get Boolean values by comparing other values.

For example, we can check if two numbers are equal using == (double equals sign).