Node.js, AJAX, and jQuery are all advanced implementation of JavaScript. However, they have a fair share of differences.
Node.js is a server-side platform that is used for developing client-server applications while AJAX, a.k.a. Asynchronous Javascript and XML is a client-side scripting technique that is primarily used for rendering the contents of a page without refreshing it. AJAX is used mainly to showcase dynamic content. jQuery is a JavaScript module that complements AJAX, DOM traversal, and looping. It is loaded with many useful functions to aid JavaScript development.