Why do you need a templating language with Node.js?
After doing some research, everyone seems to advise learning and using some form of a Templating Language with node.js. Why? Couldn't you just use HTML, and if so, how? I'm new to Node, so I downloaded Express and immediately I asked myself, "What is .jade?"
There is no requirement, but it can be much nicer. You can just as easily manually output HTML, but then you are forced to keep all of your HTML inside of JS strings at all times, or keep it in a file.
You'd do something like this:
res.send("" + content + "");
As soon as you want to have dynamic HTML, you either need to include it directly in your code, or you need to have it in a template. The difficulty is that you can't just throw standard HTML in a file, because that essentially makes it impossible to dynamically alter the page. To solve this problem, usually you'd dynamically generate HTML using some kind of Templating language like jade.
For a tiny one-off app, it may not be a big deal, but separating your presentation HTML from your code becomes very important as the size of the app you are developing grows.