I learnt that JADE is a template language and it is preferred engine for express.
What are the advantages of using JADE instead of html ? Is it possible to use html directly instead of using jade ?
Jade has a cleaner, more readable syntax and comes with filters and helpers: https://github.com/visionmedia/jade#a7
If you're going to migrate HTML files to jade, this converter might come handy: http://html2jade.aaron-powell.com/
...but you can also use HTML.
app.set('view engine', 'html');
app.set('view engine', 'html'); app.register('.html', require('ejs'));
(requires ejs be installed, which you can easily do via
npm install ejs)