First try to work out these differences at the individual or departmental levels. The Graduate Division is also available for consultation. Faculty provide encouragement, suggestions, and set the standards of scholarship, but it is not up to the committee to see that you get a degree. Most significantly, the conduct and presentation of the dissertation research is the student's responsibility. Each student-committee relationship is unique.
Some successful ones are quite formal and dis-tant, others are close and vivacious.
You may need to do a little self-assessment before you name a committee to determine what you want the committee to do for and with you. Choose one who will push you to excel.