For TiddlyWiki, Node.js means that we can have a single code base that can run in the browser or on the server, giving great flexibility in how it is used.
For end users, Node.js is no more complicated to install than a web browser, but unlocks powerful capabilities such as the ability to run TiddlyWiki as a web server that you can connect to from other devices.
Node.js is a trademark of the OpenJS Foundation. See: https://nodejs.org fore more details.
TiddlyWiki on Node.js will give an overview about the possibilities using a client-server configuration.