According to the valence bond theory(VBT), a covalent bond is formed by the overlapping of atomic orbitals containing electrons of opposite spin which pair together. However what is the physical meaning of overlapping here? Does it mean that the electrons of either orbital are now constrained to move in the region where the orbitals overlap?
Note: I know that in the case of MO theory the atomic orbitals just combine linearly(atleast approximately) to give molecular orbitals but I wonder what is the explanation that VBT provides.