WEBVTT 00:00:04.069 --> 00:00:10.019 A variable is a container that you can store a value in. When you use that variable in 00:00:10.019 --> 00:00:15.639 an algorithm, it opens up the container and looks at the value inside. This lets you write 00:00:15.639 --> 00:00:20.820 smarter algorithms that behave differently depending on the value stored in the variable. 00:00:20.820 --> 00:00:25.800 Now you're going to try playlab where you are given different games and you can change 00:00:25.800 --> 00:00:31.689 the values of variables like speed, height, score, in order to change the game. You won't 00:00:31.689 --> 00:00:37.020 have to change the algorithm of the game to change how it plays, just the variable. In 00:00:37.020 --> 00:00:41.960 my work for Kindle and on X-ray for books, we apply variables in many different ways. 00:00:41.960 --> 00:00:47.550 One way that you can use a variable is to store page numbers of a book. A user can increase 00:00:47.550 --> 00:00:53.059 and decrease the size of the font on a page. Based on the font size, the number of pages 00:00:53.059 --> 00:00:58.030 in the book can change. We can adjust it by storing the number of pages in the variable.