Quantum tunnelling is a physical phenomenon of particle behaviour in quantum mechanics. The idea of quantum tunnelling is widely used in various fields, including electronics, biology, and chemistry. Synonyms for quantum tunnelling include quantum penetration, quantum tunnel effect, and quantum barrier penetration. Other terms that relate to the concept of quantum tunnelling include wave-particle duality, the Heisenberg uncertainty principle, and quantum flux. In practical applications, quantum tunnelling is used in tunnel diodes, tunnel transistors, and scanning tunnelling microscopy. The study of quantum tunnelling has opened doors to technological advancements that have significant implications for the future of science and technology.