Update installation.md (#204)

add info for the new ReportServerUser.

implementer-guide/setup/installation.md

@@ -10,7 +10,9 @@ position: 200
 
 # Report Server Installation
 
-The Report Server web application is installed by a Windows installer which automatically creates a separate web site with its own application pool on the IIS. The web site is registered on port 83 by default. The application pool is configured to use the `LocalSystem` identity, but you can apply the [principle of least privilege](https://learn.microsoft.com/en-us/entra/identity-platform/secure-least-privileged-access) and manually create an [identity with limited permissions]({%slug how-to-change-report-server-iis-user%}). The installation process also includes registering and starting a Scheduler Windows service named `Telerik.ReportServer.ServiceAgent`.
+The Report Server web application is installed by a Windows MSI installer which deploys two applications: a web site named _Telerik Report Server_, automatically registered with its own application pool in the machine's IIS, and a non-UI application named _Telerik.ReportServer.ServiceAgent_, registered as a Windows Service. The Report Server web application by default is accessible on HTTP port 83, and the Service Agent - on HTTP port 82. 
+
+When deploying a new instance of Report Server, the default behavior of the MSI installer is to suggest applying the [principle of least privilege](https://learn.microsoft.com/en-us/entra/identity-platform/secure-least-privileged-access) and create a dedicated Windows user named **ReportServerUser** whose identity will be used by both applications. The user is granted with the minimum necessary permissions to operate within the installation folder of Telerik Report Server. The MSI installer allows to opt-out of the safe workflow and install the applications under the **LocalSystem** identity which uses elevated permissions. The safety recommendations dictate that this option should be selected only if the Report Server is deployed and used in a safe environment. If needed, the Report Server applications can be configured to use an [identity with limited permissions]({%slug how-to-change-report-server-iis-user%}). 
 
 Generally, it is possible to deploy multiple Report Server instances on the same IIS if they have different web site names, ports and application folders. However, the Scheduler Windows service cannot be duplicated and will always point to the Storage of the last installed Report Server instance. For that reason only one fully functional Telerik Report Server can be installed on a single machine.