This lecture discusses the nature of quantum computation and its advantages over classical computation. The instructor begins by contrasting classical and quantum computations, highlighting the fundamental differences in information representation and operations. The lecture delves into the reasons behind quantum speedups, such as richer operations and quantum parallelism, while also addressing the challenges posed by measurement that collapses superpositions. The instructor explores classical simulation algorithms, including tensor networks and Monte Carlo simulations, which impose restrictions on quantum computations. The discussion includes recent advancements in quantum devices and their limitations, emphasizing the significance of understanding physical restrictions in quantum computations. The lecture concludes with insights into future research directions, focusing on benchmarking quantum systems and the potential for quantum advantage in restricted computational models, particularly through transversal logical computations and error correction techniques.