There are lots of way to construct geometry. - sculpting. You start with a high density mesh and drag the points like clay. - poly modeling. You start with a

There are lots of way to construct geometry. - sculpting. You start with a high density mesh and drag the points like clay. - poly modeling. You start with a plane and extend the edges until you make the topology you want. - box modelling. You start with a cube or other primitive shape and extend the faces until you make the shape you want. - nurbs / patches : you create parts of a model by moving Bézier curves around and creating a surface between them - B-reps / parametric / csg / cad / sdf / BSP : these are all similar in that you start with mathematically defined shapes and then combine or subtract them from each other to get what you want. They’re all different in implementation though - photogrammetry / scans : you take imagery from multiple angles and correlate points between them to create a mesh