This article examines the quantum mechanics of the vacuum, highlighting its evolution from a concept of absolute "nothingness" in classical physics to a space of effervescent quantum activity. The Schrödinger equation and its relevance to understanding the dynamic nature of the vacuum are discussed, along with the Heisenberg Uncertainty Principle and its implications for quantum fluctuations in the vacuum. The zero-point energy, the cosmological constant and its relationship with the expansion of the universe, and the Casimir effect are also addressed. The article concludes with a review of emerging practical applications in fields such as quantum computing, space propulsion, and quantum cryptography, and reflects on the promising future of vacuum physics.