SQL Server Reporting Services (SSRS) is a server based scalable and extensible platform for authoring, deploying, executing and managing reports based on a variety of data sources. SSRS allows us to create interactive, tabular, graphical (using data visualization controls) or free form reports from relational, multidimensional (using MDX or DMX) or XML data sources. Furthermore it allows you to view/export your reports in a variety of formats. You can specify to create report snapshots, which show data at a point of time or you can even subscribe to your published reports.
To improve the performance of report processing, SSRS lets you enable caching for the report so that if the same report request comes again, the stored copy can be rendered in the desired format and served instead of processing it from scratch, for more information click here.