Node.js and React are two of the most popular JavaScript frameworks. Though they have some similarities, they serve different purposes and have different levels of complexity. Node.js is a powerful and complex language that has a steep learning curve, while React is a simpler library that is easier to learn.
Node.js is an open-source, cross-platform runtime environment for developing server-side and networking applications. It is built on the Chrome V8 JavaScript engine and supports a non-blocking I/O model. Node.js is used to create applications that can run on the server side and can handle a large number of simultaneous connections.
React is a JavaScript library for building user interfaces (UI). It is used for developing single-page web applications and mobile applications. React is designed to make the process of building UIs simpler and faster.
Comparing the complexity of Node.js and React is difficult as they both have their own strengths and weaknesses. Node.js is better-suited for backend applications, while React is better-suited for frontend development.