Provide support of different resolution for mobile and tablet?

I want to develop application which should support android mobile resolution as well as tablet resolution.

Q1) What is different between density and resolution?

Q2) Designer generally design application in pixel (1440x2560) how designer will take care of density what should he have to take care at time of design?

Q3) What is the best way to handle font size for different resolution/density?

Q3) Which drawable folder is represent which device resolution/density?

Q4) Application Launcher icon size for different resolution/density?

Q5) Notification icon/Statusbar icon size for different resolution/density?