SQL Server Reporting Services (SSRS) is a competitor to Crystal Reports. It's a way of defining reports, just like Crystal Reports, and an engine for running those reports.
SSRS itself is a website that hosts these reports and can serve them to users through a web interface, or can schedule them for delivery over e-mail.
As a programmer, I prefer SSRS over Crystal due, among many other things, to the fact that it's more stable and uses an XML-based report file format, unlike Crystal's old binary format. That means that certain design tasks can be done simply by editing XML if it comes down to it.