The official definition of the term
is "the effect whereby the position or direction of an object appears to differ when viewed from different positions, e.g. through the viewfinder and the lens of a camera."
While a parallax.js library does exist, the term is also used to describe an effect done through pure CSS (by assigning fixed background image attributes).
Scroll to see effect
You can put text here in the center
You can also make this an ad
The image is currently set inside a container unit. You can link the whole unit and turn it into an add, much like what Kinfolk does on their homepage.
Click the following to return to the homepage.