Democratic or participative leadership encourages participation of all members, but the final decision is taken by the leader. Once the decision is taken, the leader has to communicate it back to the group and resolve possible objections if any.
Autocratic participative decision-making implies that while possible solutions are brainstormed collectively, the responsibility of taking the final decision is still on the leader alone. Autocratic leadership style allows the organization to benefit from the collective input provided by all employees while making decisions reasonably fast.
Democratic and autocratic styles of participative leadership may seem to be very much alike, but the difference is that while autocratic leadership is more goal oriented, i.e. to get results and meet deadlines, democratic leadership is more people-oriented and quality-oriented. The advantage of autocratic decision-making over democratic is that the results are obtained much faster.
Consensus decision-making is a leadership style where the leader gives up control and responsibility of decision-making, leaving it entirely to the
group. The decision has to be approved by the majority of the group while the minority of those who don’t agree initially have to agree to go along. In other words, the decision has to be modified to remove any objectionable features so that the minority can agree with it.