Having got a brief introduction to custom post types and their roles in web applications, we will find the necessary custom post types for our forum application. The majority of our application and the data will be based on these custom post types. So, let's look at the detailed requirements of a forum application.
The main purpose of this application is to let users create topics and discuss them with other users or get answers from the administrative staff. Therefore, we have to look at two important components: forums and topics. Now, try to visualize the subsections for each of these components. It is obvious that we can sort these components into two custom post types. The following sections illustrate the detailed subcomponents of each of these models.