We use programming to instruct a computer. Computers include smartphones (such as the iPhone), tablets, game consoles (such as the PlayStation), and a lot more. We say that a computer runs a program, which means that when you open your favorite game or application (also referred to as an app) on your PlayStation or on your iPhone, the device will know how to interpret and execute the program, which in this case is your game or application. A program is simply a set of instructions that your device is able to understand. We can also consider these instructions as a recipe for the device. The recipe will tell your iPhone what your favorite game is all about-everything from the colors of your avatar, to the text in the menus, to what happens when you tap on an enemy or on an animal in a game. This recipe can be written in many ways depending on your personal preference and the device that is supposed to run it. The programming language refers to the language you choose to write your program in. 

This chapter will go through the following topics: