Node.js is a platform for writing JavaScript applications outside web browsers. This is not the JavaScript we are familiar with in web browsers! For example, there is no DOM built into Node.js, nor any other browser capability.
Beyond its native ability to execute JavaScript, the bundled modules provide capabilities of this sort:
- Command-line tools (in shell script style)
- An interactive-terminal style of program that is Read-Eval-Print Loop (REPL)
- Excellent process control functions to oversee child processes
- A buffer object to deal with binary data
- TCP or UDP sockets with comprehensive event-driven callbacks
- DNS lookup
- An HTTP, HTTPS and HTTP/2 client/server layered on top of the TCP library filesystem access ...
