SSRS reports using Sharepoint server

I am new in SharePoint and SQL server reporting services. I have to create SSRS report and data source is SharePoint server. I want to know which one is better option to create SSRS report, directly through SharePoint list or by using database (not SharePoint database). I want to know advantages and disadvantages of creating SSRS reports using SharePoint list and SQL server database. As I goggle it but not getting proper answer which works for me.

Any help and links will be appreciated.

Thanks.