IntelliJ IDEA provides support for developing enterprise Java applications based on the Java EE and Jakarta EE frameworks. All the required plugins are bundled and enabled by default in IntelliJ IDEA Ultimate. The main plugin is Java EE Platform for the core platform support, such as a dedicated project wizard. There is also a number of other plugins that start with Java EE in their name and add support for various specifications, such as JPA, JSF, JAX-RS, and so on.
Depending on the set of plugins that you have enabled, IntelliJ IDEA does a lot of routine setup work for you. For example, it can create a Web or a JavaEE Application facet in your project, generate and update deployment descriptors and manifest files according to your project settings, add artifact configurations (JAR, WAR, EAR), detect problems and errors with how your application is configured. There are also run configurations for most of the supported application servers, which start the corresponding server if necessary, build and deploy your artifacts, and can even open a predefined URL in your web browser. This greatly reduces the amount of manual setup and routine tasks.
If you are new to enterprise Java development, start with Tutorial: Your first Java EE application. Then you can read more about the supported application servers and cloud providers. And learn how to develop your own RESTful web service.