Answer:
They essential for the formation of layers in a 3-D model.
Step-by-step explanation:
Stereolithography is 3D printing process in which a 3D model can be created. In stereolithography technology, there is vat of the UV curable photopolymer which is placed below in lower compartment of machine.
When the machine begins to construct 3D model by the scanning and the building of one layer at one time. Each layer in the model is constructed with UV laser and as laser traces next layer of object material hardens on contact.
Once layer is complete, platform slips down to make room for next layer. This is how, a model is created.