A simple majority requires more than 50% of the given votes.
An absolute majority requires more than 50% of all members, irrespective of the number of those voting.
Decision by qualified majority in the Council of Ministers currently requires 232 out of 321 votes. The votes of the Member States are weighted.
From 2007, in an EU of 27 countries, it is envisaged to be 258 out of 345 votes.
In the EU Constitution a system of double majority is proposed. This means that there shall be 55 % of the member states representing 65% of the population of the EU to adopt an act. At least 4 countries must back up a decision for it to com into force.
Including the population factor mainly benefits the bigger countries will the "one country one vote" element benefits the smaller countries. This system make it easier to take decisions.
LinksSee also Voting in the Council.