String interpolation

String interpolation is a way to take information from one place and use it in another. Imagine you want to make a sentence that says "I have 3 apples." If you have a variable named 'num_apples' and it stores a number (like 3), you can use string interpolation to write a sentence like this without having to type out the number 3 every time. String interpolation takes the information stored in the 'num_apples' variable and puts it in the sentence, so the sentence would look like this: "I have #{num_apples} apples."