Node.js is not a requirement for using Angular, yet if you wish to deploy and host an application, then Node.js is necessary. Node.js is a fast and efficient cross-platform JavaScript runtime environment used for creating server-side and network applications. Additionally, Node.js offers developers the means to interact with the server, create real-time applications, and create a back-end for the application. Thus, if you need to create a dynamic, interactive web application, then the combination of Node.js and Angular is a wise choice.