This document provides an introduction to TypeScript 101. It discusses TypeScript as JavaScript with types and tools. TypeScript compiles to JavaScript. The document outlines reasons for using TypeScript like security, structure, and updates. It also discusses when TypeScript should be used, like on large projects and for optimization. It then covers TypeScript types like Boolean, Number, String, Array, Enum, Any, and Void. The document also discusses TypeScript statements like if, for, while, do...while. It shows changes made by TypeScript like adding types to variables, enums, classes, and functions. The document concludes with discussing advantages and disadvantages of TypeScript and providing additional resources.