As TypeScript is a superset of JavaScript, before we start learning about its syntax, it'll be easier to start by introducing some of the bigger changes in ES2015 and ES2016; to understand TypeScript, we first must understand ES2015 and ES2016. We will have a whistle-stop tour through these changes before diving into TypeScript properly later.
A detailed explanation of ES2015 and ES2016 is outside the scope of this book. In order to get familiar with all the new features and syntaxes, I strongly recommend that you take a look at Exploring ES6: Upgrade to the next version of JavaScript by Dr. Axel Rauschmayer.
The next couple of pages will introduce new standards and allow you to take advantage of most of the features you will need during the development of Angular applications.