Transpiling is the process to convert the typescript into javascript in a auto manner. Traceur, a JS compiler are used for the same.
TypeScript is a typed superset of JavaScript which compiles to convert to JavaScript. It offers classes, Interfaces and modules to
help you build robust components. Write the transpile to JavaScript are often called compile-to-JS languages, and are called to target JavaScript.
However typescript is also used to write code in the Angular applications and code is internally transpiled into javascript