We use transformations to change objects, to rotate them around an axis, to stretch or shrink them along some direction, to move them to another place. In particular, we can use them to position and orient them in space as we like, rather than having them cling to the principal axes along which they are typically designed. It’s usually helpful to think about transforming the coordinate spaces in which objects live, rather than the objects themselves. We talk about these things in this section.