Hover triggers change by changing innerHTML property:

Hover Over Me

This button opens another window in full screen:

Click triggers change in position of block:

Click Me!

Hover toggles visibility of block:

Hover Over Me!

The difference between hiding a block with the CSS display property compared to the CSS visibility property consists of the visbility property cutting out a space in the layout for when the content will be visible. However, the display property will completely remove the element, eliminating the space dedicated to the block in the layout.