There are mainly 3 components of TypeScript:
Language – The most important part for developers is the new language. The language consists of new syntax, keywords and allows you to write TypeScript.
Compiler – The TypeScript compiler is open source, cross-platform and open specification, and is written in TypeScript. Compiler will compile your TypeScript into JavaScript. And it will also emit error, if any. It can also help in concatenating different files to a single output file and in generating source maps.
Language Service – TypeScript language service which powers the interactive TypeScript experience in Visual Studio, VS Code, Sublime, the TypeScript playground and other editor.