What does "adverse selection" mean in economics?

Adverse selection is the distortion of market resource allocation caused by information asymmetry in economic phenomena. If the information is completely equal, the neutral 2+2 thinking mode is adopted, and the two sides' value cognition of the same thing is completely objective, then it is the same and there is no motivation to exchange. Therefore, from the perspective of "2+2", the so-called reverse is just the reverse exchange of the other direction. Due to the reality of asymmetric information, both parties' choices are so-called reverse, not limited to the party holding monetary goods. Buying and selling are mutual. We only see the adverse selection of the buyer who holds the currency, but not the adverse selection of the seller. It cannot be said that it is influenced by the narrow thinking mode of 1+ 1. The opposite view is just a name given by economists to this economic phenomenon. The possible starting point is to hope that people can consider each other's feelings and ideas with reverse thinking, rather than simply understanding the world from their own perspective.