There are two basic kinds of committees. These committees serve the same term as officers of the group and are generally standard for the group. There are both advantages for the individual and advantages for the group in using committees. An opportunity is provided to do something of interest. Leadership experience is provided.
More ideas emerge from group interaction.
Those involved in making a decision are committed to the ideas. Many members have connections with resources for implementing a decision. The desirable thing about a committee is that it operates informally. A chairman usually is appointed and he asks someone to record minutes of the meeting and to prepare a report. Keeping the committee on task.