Crystal reports in windows application

Is this crystal reports is used only in windows application?
-- No, you can use it with windows and web both.
How important this crystal reports.
-- Reports are definitely important, but crystal reports is just a tool to generate the reports. You can consider other options as well.
If a project without crystal report is good?
-- As long as you deliver good reports, it doesn't matter what you use.
What is the main purpose of this crystal report?
-- To generate reports, obviously.