If you’ve worked with other programming languages, you might be familiar with the concept of data types. Simply put, there are different kinds of data in the world around us: numbers, letters, dates, huge numbers, pictures, and more. Most programming languages need to understand what kind of data a variable will contain, so that the language can treat the variable appropriately. For example, it wouldn’t make sense to try to subtract the word Hello from a picture of a flower, and so most programming languages won’t allow you to perform mathematical operations with anything but numeric variables. Languages that care about the type of data a variable will hold are called strongly typed languages.
