thanks for your help , that's what I was looking For

I'd like To know the Difference Between Tap And Click when Assigning Event ?
I'm Making An App for Android Device ,So I'm Worried Whichone Is more Preffered , they seem to do the same thing ?

how To get the image associated with a database to be displayed in the app
I want my application to scan for barcode and search database for name,type,and most importantly for images (of the product).?!
how to reach the image and create a service for that ?