Loft is a variant of a wireframe volume of the 3D object, a technique used in 3D modeling packages such as Onshape, 3D Studio Max, Creo*, SolidWorks, and NX. It's developed from planar sections spaced along an approximate path.
Consider lofting in boat building to visualise the process, the planar sections are the boat ribs spaced along its length. The planking then forms the 3D volume as it develops a smooth skin between the ribs.
In PTCs Creo it is referred to as a Blend or Swept Blend.
References
Loft (3D) Wikipedia(Text) CC BY-SA