An interchange format defines a protocol for data delivery so that these same data are "understood" by another software.

In terms of point clouds, it is fairly simple because the number of existing formats is still low and the amount of information assigned to each point is itself limited (X, Y, Z, Intensity, Color, Normal).

However, there are formats that sort points in a grid, which gives them advantages in computation time of certain parameters, like normals.
These formats (PTX, PTZ, BSF, TZS, ...) are proprietary of their respective publishers, which limits their compatibility.