CSS: Hide Element (visibility)
A element can be hidden by:
visibility: visible
- normal.
visibility: hidden
- maket it invisible, but it still occupies the same space.
display: none
- make invisible and occupies no space. (effectively as the element doesn't exist.)
These are useful especially when used together with JavaScript. For example, for collapsible list, popup tooltip.
〔see How to Create Tooltip〕