Direct democracy is a regime in which the adult citizens as a whole debate and vote on the most important political decisions, concerning matters on which, in representative systems, parliament now debates and votes, and where their vote authoritatively determines the actions to be taken.
The essential feature of direct democracy – citizens taking the important decisions – is compatible with many types of institutional arrangements, including existing representational ones. Thus, substituting popular voting on the most important decisions does not necessarily mean that parliaments need be abolished. They could be retained in a variety of roles. One would be as a committee to debate and set the wording of the policy alternatives to be voted on by citizens. Another would be to stage an advisory debate or even and advisory vote on the matter under discussion. Still another would be to oversee detailed administrations of policies endorsed by the population.