This lecture discusses the capacitive coupling of two qubits, focusing on the iSWAP and SWAP gates. The instructor explains the transition from using capacitors to Josephson junctions, emphasizing the significance of the two-state system in quantum mechanics. The lecture covers the Hamiltonian for the coupled qubits, detailing the energy states and their interactions. The instructor introduces the concept of resonance and how it affects the coupling between qubits. The discussion includes the implications of changing inductance on the coupling strength and the conditions for coherent state transfer. The lecture also touches on the measurement techniques used to observe qubit states without destruction, highlighting the importance of non-demolition measurements in quantum computing. The instructor concludes by discussing practical applications and the theoretical framework that supports these quantum interactions, providing insights into the future of quantum technologies.