The consensus and conflict perspectives are two different views on the origins and the nature of laws. As their names suggest, the former perspective holds that laws come about through a process of consensus while the latter suggests that they come about through conflict.
In the consensus perspective, laws are the embodiment of a consensus in society. This is a consensus that helps to hold society together and allows it to function smoothly. In this view, the law is a good thing for all in society. The law helps to keep society running well because it enforces rules that a society has developed together over time. These rules have been developed through consensus because they are beneficial for the society.
The conflict perspective has a much less benign and harmonious view of the laws. In this view, the laws are imposed by whatever group prevails in conflict within the society. Society is full of conflict between different groups (men and women, different economic classes, different races and ethnicities, etc.). The groups that win their conflicts get to make the laws. They then make laws that will help to keep them in power and will help to keep their antagonists in a subordinate position. Thus, the laws are not developed by a consensus of society but are instead a tool to be devised and used by the dominant classes.
Thus, we can see that these two perspectives have very different views of the nature and origin of laws.