VBT uses hybridisation to explain geometry: sp3 (tetrahedral), dsp2 (square planar), sp3d2 or d2sp3 (octahedral). Inner orbital complexes use (n-1)d orbitals (d2sp3) — low spin; outer orbital complexes use nd orbitals (sp3d2) — high spin. Limitations of VBT: Cannot quantitatively explain colour, does not predict spectrochemical series, fails for distorted complexes. CFT advantages: Explains colour (d-d transitions), magnetism (spin state), spectrochemical series (Delta values), and thermodynamic stability (CFSE). CFT limitation: Treats bonding as purely electrostatic — cannot explain pi-bonding or why CO/CN- are strong field ligands $\frac{requires Ligand Field Theory}{MOT}$.