Consensus over unanimity
When people seek for unanimity, decision making can be simplified with a Yes or No most of the time. But the human mind is more diverse and is thus restrained by this binary approach.
The planning poker in Scrum team is a good example. The objective is to get an idea on how difficult a given task is. The team member will draw a card depending on their opinion on a defined feature. The overview or shades of numbers gives an estimation: is it difficult or not compared to the rest of our tasks.
As in the planning poker, the consensus card will give you a direction: is the team agreeing or disagreeing on a certain proposition. The consensus becomes the decision of the group.