The term pop-up book is often applied to any three-dimensional

Three-dimensional space

Three-dimensional space is a geometric 3-parameters model of the physical universe in which we live. These three dimensions are commonly called length, width, and depth , although any three directions can be chosen, provided that they do not lie in the same plane.In physics and mathematics, a...

 or movable book, although properly the umbrella term movable book covers pop-ups, transformations, tunnel books, volvelles, flaps, pull-tabs, pop-outs, pull-downs, and more, each of which performs in a different manner. Also included, because they employ the same techniques, are three-dimensional greeting card

Greeting card

A greeting card is an illustrated, folded card featuring an expression of friendship or other sentiment. Although greeting cards are usually given on special occasions such as birthdays, Christmas or other holidays, they are also sent to convey thanks or express other feeling. Greeting cards,...

s.
Design and creation of such books is part of paper engineering, a term not to be confused with paper engineering

Paper engineering

For other uses, see Paper foldingPaper engineering is a branch of engineering that deals with the usage of physical science and life sciences in conjunction with mathematics as applied to the converting of renewable raw materials into useful and valuable products...

- the science of paper making.