How do I position one image on top of another in HTML?

Question

I\'m a beginner at rails programming, attempting to show many images on a page. Some images are to lay on top of others. To make it simple, say I want a blue square, with

Answer 1

Create a relative div that is placed in the flow of the page; place the base image first as relative so that the div knows how big it should be; place the overlays as absolutes relative to the upper left of the first image. The trick is to get the relatives and absolutes correct.