TypeScript is different from JavaScript in the following manner:

We need TypeScript:

• TypeScript is fast, simple, and most importantly, easy to learn.
• TypeScript supports object-oriented programming features such as classes, interfaces, inheritance, generics, etc.
• TypeScript provides the error-checking feature at compilation time. It will compile the code, and if any error found, then it highlighted the errors before the script is run.
• TypeScript supports all JavaScript libraries because it is the superset of JavaScript.
• TypeScript support reusability by using the inheritance.
• TypeScript make app development quick and easy as possible, and the tooling support of TypeScript gives us autocompletion, type checking, and source documentation.
• TypeScript supports the latest JavaScript features including ECMAScript 2015.
• TypeScript gives all the benefits of ES6 plus more productivity.
• TypeScript supports Static typing, Strongly type, Modules, Optional Parameters, etc.