Unanimity is agreement by all people in a given situation. Groups may consider unanimous decisions as a sign of social, political or procedural agreement, solidarity, and unity. Unanimity may be assumed explicitly after a unanimous vote or implicitly by a lack of objections. It does not necessarily mean uniformity and can sometimes be the opposite of majority in terms of outcomes. 
"Pareto efficiency" is an economic concept of a state in which no reallocation of resources can make everyone at least as well off.
- Some of the prose of the first paragraph was originally copied from the first paragraph of w:Unanimity on September 7, 2022 (from https://en.wikipedia.org/w/index.php?title=Unanimity&oldid=1089747627 )