Logs logic implementation in ABAP

Dear Forum Gurus

I work in SAP for 6 years but sincerly I have never implemented any logs logic in SAP for client application. Do you have any idea how to do it. Is there any class for it. I mean - I have the application some errors occured while running and then I want to send to user the information about this erros in some logs table or something like that. Are there any standards for that?

Thank you in advance Bogusia!