Valence bond (VB) theory assumes that all bonds are localized bonds formed by sharing electrons in overlapping atomic orbitals.
VB theory explains sigma and pi bonds in terms of end-on and side-on overlap of atomic orbitals.
It explains hybridization in terms of mixing of atomic s, p, and d orbitals.
VB theory explains the shape of molecules in terms of VSEPR theory.
In short, VB theory is the theory that you have been learning all along.