Short answers, pulled from the story.
A state is Pareto-optimal if no alternative exists where at least one participant's well-being rises while nobody else's falls. When no further improvements are possible, the state reaches a Pareto optimum.
Vilfredo Pareto lived from 1848 to 1923. He was an Italian civil engineer and economist who studied economic efficiency and income distribution.
Engineers identify a subset called the Pareto front or Pareto frontier where no other choice outperforms it categorically. Designers restrict their attention to choices within this efficient set rather than considering every parameter range.
Natural selection pushes bacterial genes toward the Pareto frontier for resource and translational efficiency. Genes near the frontier balance cost against speed of production effectively to ensure survival through efficient allocation of cellular resources over time.
Critics argue that Pareto efficiency ignores wealth inequality and conflicts with individual liberty principles. An economy where a wealthy few hold vast resources can still be Pareto-efficient despite extreme disparity.