What is the architecture of the SQL server reporting services?

Reporting Services are a combination of multiple components. As mentioned in the below screenshot it has below component:

1. Report Server Database: As and when you are doing any installation of reporting services, you have to store the reporting services database at some place.
   
2. Report Manager: this is web-based utility which provides complete management of report structure and authorization from consumer standpoint.
   
3. Report Server: this is web hosting service which host the report manager. As report manager is a web application, it should have a server associated with it.
   
4. Report Builder: this is a web-based tool to provide end user an ability to develop the report.
   
5. Report Designer: in a nutshell, this is your SSDT i.n. SQL SERVER DATA TOOL