  'Holographic' relations between theories have become an important theme in
quantum gravity research. These relations entail that a theory without gravity
is equivalent to a gravitational theory with an extra spatial dimension. The
idea of holography was first proposed in 1993 by Gerard 't Hooft on the basis
of his studies of evaporating black holes. Soon afterwards the holographic
'AdS/CFT' duality was introduced, which since has been intensively studied in
the string theory community and beyond. Recently, Erik Verlinde has proposed
that even Newton's law of gravitation can be related holographically to the
`thermodynamics of information' on screens. We discuss these scenarios, with
special attention to the status of the holographic relation in them and to the
question of whether they make gravity and spacetime emergent. We conclude that
only Verlinde's scheme straightfowardly instantiates emergence. However,
assuming a non-standard interpretation of AdS/CFT may create room for the
emergence of spacetime and gravity there as well.
