Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine. Node.js is single-threaded and uses an event-driven, non-blocking I/O model that makes it lightweight and efficient.
Understanding Node.js
Understanding non-blocking I/O
An input or output operation (I/O) is an operation that requires writing or reading from a physical source. This includes things such as saving a file into your hard disk or sending a file through the network.
In the past, operating systems only allowed us to perform I/O operations in what is known as a blocking model. In a blocking model, we can run an application in a thread, but when an I/O request takes place, the thread is blocked until the request is completed.
Web servers implemented...