In this lesson, we’ll explore the building blocks of a programming language - data types and variables. A data type represents the type of value an object possesses. Here are a few of the types of data supported in Kotlin:

• String: a sequence of characters enclosed in double quotes
• Integer (Int): whole numbers and their opposites
• Boolean: true or false values

Each variable in a Kotlin program will possess one of these types of data. Think of a variable as a unique, virtual container holding a certain piece of information that can then be used and referenced throughout a program.

Take a look at the animation on the right. Each item represents a variable holding a specific type of data dependent on its value. Codey packs their backpack with a lunchBox holding the value "sandwich" and a waterBottle with 32 ounces of water. tentPacked holds a Boolean value which represents if the tent is in Codey’s backpack. With these values, we can then write a program that checks if Codey has everything they need for their journey.

This is just one of many programs we can build with these variables. Each variable would have its own place and purpose in a program, and their respective data types determine how we can interact with them.