Does opacity:0 have exactly the same effect as visibility:hidden

Here is a compilation of verified information from the various answers.

Each of these CSS properties is unique. In addition to rendering an element not visible, they have the following additional effect(s):

1. Collapses the space that the element would normally occupy
2. Responds to events (e.g., click, keypress)
3. Participates in the taborder

                     collapse events taborder
opacity: 0              No     Yes     Yes
visibility: hidden      No     No      No
visibility: collapse   Yes*    No      No
display: none          Yes     No      No

* Yes inside a table element, otherwise No.