here you go rusp https://en.wikipedia.org/wiki/Bra%E2%80%93ket_notation
Bra–ket notation
Bra–ket notation, also called Dirac notation, is a notation for linear algebra and linear operators on complex vector spaces together with their dual space both in the finite-dimensional and infinite-dimensional case. It is specifically designed to ease the types of calculations that frequently come up in quantum mechanics. Its use in quantum me...
en.wikipedia.org