If you are part of a group, working for a company or a club then you will have to make several decisions. Making decisions in a group has its advantages and disadvantages:
Advantage 1: There are many more people to contribute to the discussion, meaning more ideas. This means if there is a problem things can be solved more quickly, and solutions are generally of a better quality. For example if there was an architecture firm, and they needed some ideas to make a bridge, then if there was just one architect on the project he might use a suspension bridge, but if there was a group then others would have suggested an arch bridge, which would have been more appropriate for the situation.
Advantage 2: As there is a group discussion going on, then everyone will be interacting with one another, so people will get to know each other better.
This brings the people in the group closer together and the group will begin to become a team, as they are all working together. If the decisions were made by votes in a box, then there wouldn't be as much interaction between the members, and wouldn't promote teamwork or spirit.
Disadvantage 1: Usually not everyone will agree with what has been decided, and the minority will disagree with the majority, which, instead of bringing the group further together will cause arguments and perhaps even factions in the group. For example if one group wanted to donate 25% of all earnings to charity, and another group wanted to donate 10%, then if things escalated the members would divide into two groups and the people who wanted to donate a quarter would see the others as stingy, and thus there would be factions.
Disadvantage 2: Decisions will take a lot...