I have created a SSRS report. In the report viewer I saw 2 security sections
What is the difference between
While the answer of Kavin may suits your needs note that it is not 100% matching your requirements: The Browser role does not have only the right to view reports and folders, it can also:
The My Reports role can do a lot of extra things you may not want to grant:
The Publisher role have far less rights than the My Reports one, and will add just the Manage models task.
I think the best option you have is to create custom roles.
To do so with SSRS 2008, you need to connect using SQL Server Management Studio, selecting the Reporting Services Server type.
You will be able to manage roles from there. Here is a MSDN article that will help you.
Back to your requirements, I think the custom roles you should create are (name them as you wish as long as you don't use an existing name):
Report Viewer:
Report Manager:
Then go back to the site settings and they will available as any other system role.