Report parameters concepts in paginated reports (Report Builder)
Applies to: 
Microsoft Report Builder (SSRS)
Power BI Report Builder
Report Designer in SQL Server Data Tools
You can add parameters to a paginated report to link related reports, to control the report appearance, to filter report data, or to narrow the scope of a report to specific users or locations.
Note
You can create and modify paginated report definition (.rdl) files in Microsoft Report Builder, Power BI Report Builder, and in Report Designer in SQL Server Data Tools.
Report parameters are created in the following ways:
Automatically, when you define dataset query that contains query variables. For each query variable, a corresponding dataset query parameter and report parameter with the same names are created. A query parameter can be a reference to a query variable or to an input parameter for a stored procedure.
Automatically, when you add a reference to a shared dataset that contains query parameters.
Manually, when you create report parameters in the Report Data pane. Parameters are one of the built-in collections that you can include in an expression in a report. Because expressions are used to define values throughout a report definition, you can use parameters to control report appearance or to pass values to related subreports or reports that also use parameters.
For more information, see Report Parameters (Report Builder and Report Designer).
Parameters are frequently used to filter report data both before and after the data is returned to the report. For more information, see Filter, Group, and Sort Data (Report Builder and SSRS).
When you design a report, report parameters are saved in the report definition. When you publish a report, report parameters are saved and managed separately from the report definition. After you save the report to the report server, you can do the following:
Change report parameter values directly on the report server independently from the report definition.
Create multiple linked reports in which each linked report is a link to the report definition with a separate set of parameter values that can be managed independently on the report server.
If you plan to create report snapshots, histories, or subscriptions to a published report, you must understand how report parameters affect the design requirements for the report.