Dirac-Bra Notation

Dirac bra-ket notation is a system used in quantum mechanics to describe states and their relationships. A "ket" (|ψ⟩) represents a specific quantum state, like a point in a complex vector space. A "bra" (⟨φ|) is the dual of a ket, essentially a mathematical function that acts on a ket to produce a number called an inner product, indicating how similar or related two states are. This notation simplifies calculations involving quantum states, allowing physicists to elegantly express probabilities, measurements, and transformations within the quantum framework.