S.T.E.M. study often requires being able to visualize things that are not obvious. Posters can help, but posters fall short if three-dimensional views are needed. Fortunately, three-dimensional models are available. Using a three-dimensional model can put things in perspective much better than two-dimensional representations can.
In some cases, three-dimensional models are inadequate. In those cases, showing how things change over time is very important in understanding the process being studied. Working models can help when a four-dimensional representation, the fourth dimension being time, is paramount in understanding a process.