Choosing the proper types to model your data in complex applications is important. Most of the time you'll reach for primitive types that get the job done well.

Primitive types have their downsides which we'll explore in this lesson. The main take away here is that when you have different kinds of a primitive type, you can start running into issues when processing that data. For example, an object's 'id' and a property on the object of 'salary' might both be of type number but you would never want to add these two values together.