https://en.wikipedia.org/wiki/Consensus_decision-making alternative political movements care a lot about how decisions are taken. For instance, authors like David Graeber consider that majority voting only makes sense in the context if backed by violence.
So what percent of people are required for "consensus" because it seems like 50%+1 to 100%. There seems to also be an implication that democracy is 50+1 when it isn't. It can require any percentage to reach a decision.
Those two words refer to the same "type" of system where the members make a decision by ascent or descent. Both systems require an agreed upon barrier of acceptance.
They are the same. The US congress reaches decision by consensus.