JavaScript in Node.js
One important consequence of the architecture we have just analyzed is that the JavaScript we use in Node.js is somewhat different from the JavaScript we use in the browser.
The most obvious difference is that in Node.js we don't have a DOM and we don't have a window or a document. On the other hand, Node.js has access to a set of services offered by the underlying operating system that are not available in the browser. In fact, the browser has to implement a set of safety measures to make sure that the underlying system is not compromised by a rogue web application. The browser provides a higher-level abstraction over the operating system resources, which makes it easier to control and contain the code that runs in it, which will also inevitably limit its capabilities. In turn, in Node.js we can virtually have access to all the services exposed by the operating system.
In this overview, we'll take a look at some key...