Two important parts of SQL Server Reporting Services administration have to do with what Microsoft calls "Site Settings" and managing folders.
NOTE: When SSRS is first installed, only user accounts in the local Administrators group can see the Site Settings and Manage Folder links. For initial server setup (SSRS version through 2016) it has been necessary to run Internet Explorer as administrator on the local server to have access to all of the necessary configuration functionality that those pages expose.
Within the SSRS UI, we reach the Site Settings and folder management pages using the links in the screen captures below. If those links are not visible, the account being used does not have the necessary permissions.
Administer SSRS Site Settings
Administer SSRS Folders
Site Settings
When SSRS is first installed, the only accounts with access to the Site Settings link are those in the local Administrators group for the server. Once other accounts are added to the System Administrator role (and given Content Manager rights--see below), they will also see the Site Settings link. Generally speaking, the Site Settings page can be used for:
Setting the application title
Setting server-wide defaults for report history limits and report processing timeout values
Managing system-level role assignments (System User or System Administrator)
Managing shared schedules
Folder Management
In order to reach the folder management screens in SSRS, a user must be a member of the Content Manager role for that folder--when the server is first installed, users in the local Administrators group are the only ones with this access. All of the different administrative tasks available to Content Managers are listed below.