Transparent container is an UI element, we can insert other UI elements into it, using this we can format design of a web dynpro screen(view).
Step1: Go to SE80, create a web dynpro component ZSAPN_TRANSPARENT_CONTAINER.
Step2: Go to Main view, go to layout, right click on rootuielementcontainer ->insert element, provide id as T1, type as 'TransparentContainer'.
Step3: Transparent container is inserted.
Step4: Now you can insert other UI elements into it.