What is the use of "element{visibility:hidden}"

Question

Why do you want to hide the content? than just dont write it right?

Answer 1

Well.. you could hide it at first and when the user interact with the page (maybe after pressing a button) you can make it appear using javascript...

Answer 2

to hide the content from reader of page, but actually it is there and still take the same space hidden content still affect the layout of page.
we use visibility:hidden to give dynamic effect to page and element will appear on user input

Answer 3

elementX{
visibility: hidden;
}

code above hides the specified elementX, but that elementX will still take up the space as if it was not hidden from a normal flow..