In computing the electric field at a point call it point P in the first quadrant of a Cartesian coordinate system because of a continuous charge distribution from 0 to L on the x-axis we must take into account the fact that each element of charge makes a vector contribution to the electric field at point P that is in a different direction than that of the vector contribution from any other charge element. The vector contributions should be added as vectors and we usually deal with this by adding the x-components of all the vector contributions to get the x-component of the total electric field at point P then adding the y-components to get the y-component of the total electric field and finally putting the components together to write an expression for the total electric field.

Now suppose that we are computing the magnetic field at point P to a wire segment that carries current along the x-axis from 0 to L. Does the reality that the contribution to the magnetic field due to each infinitesimal element of the current-carrying conductor is a vector leads to the same complications that we find in the case of the electric field due to a line segment of charge?