Hi - What version of InfoPath are you using? Are you using SharePoint?
Forms can be submitted to a form library and promoted properties can be used to display form data in the library. You can base a form off a database to allow submitting data there. You can export to Excel - and InfoPath gives you options of a single or multiple forms. You can use a third party product (or custom code) to save data to SharePoint lists or SQL (i.e, DBXL, qRules).
Here's an Office Online page that may help as well - it was written for IP 2003, but is still relevant.
http://office.microsoft.com/en-us/infopath-help/what-can-i-do-with-the-data-collected-in-a-form-HA001122794.aspx