Canonical quantization is a rather formal way to turn a classical

(non-quantum) particle or field theory into a corresponding quantum

theory. It is useful, if you don't have an intuitive picture of precisely

how the quantum theory should work. First you write a Lagrangian for the

classical theory, choose the dynamical variables, work out the canonical

momenta for those variables, turn the variables and momenta into

operators, then impose commutation relations for the operators to account for

quantum fuzziness.