Vectors that are all in the same plane are defined as:

Vectors that are all in the same plane are defined as coplanar. This means that the vectors can be drawn on a flat surface without requiring any three-dimensional projection. When vectors are coplanar, they are influenced by the same set of physical laws within that plane, such as the principles of equilibrium or the vector addition process.

In contrast, scalars represent quantities that do not have a direction and thus do not fit into a context requiring a plane or directionality. Concurrent vectors refer to vectors that act at a single point, regardless of their plane, and thus do not necessarily imply being in the same flat surface. Resultants are the vectors that sum multiple vectors together but do not describe the relationship regarding their alignment in a plane. Therefore, the correct term for vectors lying in the same plane is coplanar.