EU directives lay down certain end results that
must be achieved in every Member State. National
authorities have to adapt their laws to meet
these goals, but are free to decide how to do so.
Directives may concern one or more Member States,
or all of them.
Each directive specifies the date by which the national laws must be adapted - giving national authorities the room for manoeuvre within the deadlines necessary to take account of differing national situations.
Directives are used to bring different national laws into line with each other, and are particularly common in matters affecting the operation of the single market (e.g. product safety standards).