@ceruds What i know is that usually creating a 3D model involves two main techniques: Sculpting or Polymodeling

Sculpting involves using tools to change the shape of a finely divided mesh, which lets you add a lot of detail. Think of it as shaping a bar of modeling clay. However, these models usually have too much triangles to be considered for stuff like animation or videogame development, so you need to usually do something called "Retopology", which basically is "tracing" the sculpted model by putting polygons on top of it to reduce the amount of detail.

Polymodeling or Box modeling is just manipulating primitives (planes, boxes, cylinders, spheres, etc) to create your desired model. In this case you have to move and extend the geometry of the primitive to create the desired shape. This modeling technique is best used for stuff that doesn't require a great amount of detail.

There are other modeling techniques like parametric modeling, NURBS, but those are used on other kinds of scenarios, like industrial modeling and such.