TypeScript is a programming language which is presented as a package in Node.js ecosystem.
By using this package, you can:
1. Make concise (absolute) imports in your project.
2. Create custom types for your request & response payloads.
3. Use intellisense & type checking features to make less syntax mistakes in your code.
Custom types also act as a documentation for your payload data - you won't have to check with your external collections/tools for this anymore!