teah me

i want to know the meaning and use of " <div> " tag

 

It has no "meaning" it just groups sections together:

http://www.w3schools.com/tags/tag_div.asp

 

could i place any object over picture in html

 

Little unsure what you're asking, but i'm assuming you're going on about layering? Could be wrong, but yes, you can with div tags and css script. Just change the z-index number.