Questions

1) What is TypeScript ?
TypeScript is a superset of JavaScript and uses the file extensions ".ts" and ".tsx".
TypeScript comes with the tsc compiler that compiles your code to ES 2009 (ES5) and creates the *.d.ts files that contain your type declarations.
TypeScript includes a lot of features found in ES 2015 plus some extra stuff (eg Interfaces)

2) What is ts-loader ?
This is a webpack plugin that can load Typescript.

ts-loader 

3) What is the 'omit' type ?

4) When would you need to use the 'declare' keyword ?

5) How can you get 'declaration files' automatically ?
Set the declaration option to true in the tsconfig.json file

6) How can you overload a function ?

7) How can you make all the properties of an interface optional ?

8) Where can decorators be applied ?
Classes, properties, methods and metho arguments

9) What is the 'Record' type ?

10) When would you use the 'unknown' keyword ?

11) What is a '.map' file and when would you use it ?
This can be used when you are debugging
This file can be generated by setting the sourceMap option to true in the tsconfig.json file