Normative Influence
Normative influence is what people or sometimes society deems as normal/acceptable behavior. As people or a person grow, we look for social queues from the people around us to better establish guidelines for acceptable behaviors and this is normative influence. For example, most people do not pick their noses in public because a lot of people were taught growing up that it's not appropriate in a public setting.
Conformity
Conformity is impulse to do what others do candidly because others are doing it. This reaction has a bit of the normative influence that plays a role in it as well. We as humans conform to what we think is a mundane norm in society or just in general. For instance, a group of teens could befriend a new student at school and that new friend/student could easily conform to the social characteristics and behaviors of the group that befriended that new student all because that new student was invoked into how the group acted. The new student conformed possibly to fit in with the group.
Obedience
Obedience is the trend to do what those who are seemingly more powerful than us, tell us what to do. When we growing up, our parents or obedient with us because they are the adults and are in the more powerful stance of the relationship and we as their children tend to do what they tell us. Obviously this isn't always the case but they make rules and we follow them to make them happy and to keep us out of harms way. Obedience can be a bad thing as well. Take for example a boss at work, if that boss is taking advantage of you and overworking you or not treating you fairly yet you're still abiding by his/her demands then that is unfair treatment in the work place thus proving that obedience doesn't always work in the ways we want/hope.
References:
Schacter, Gilbert, & Wegner (2011) Introducing Psychology: First edition. Social Psychology. New York: 41 Madison Avenue
Schacter, Gilbert, & Wegner (2011) Introducing Psychology: First edition. Social Psychology. New York: 41 Madison Avenue