exploration–exploitation tradeoff (intro)

Picture a new town with one restaurant you already like. Every night you face a choice: return to the reliable favorite (exploit) or try an unknown place that might be even better—or a letdown (explore). Stick only with the known and you may miss something great; gamble too often and you waste meals on duds. RL agents face this dilemma at every step.

Exploitation uses current knowledge to grab the best reward you know about; exploration sacrifices some immediate reward to gather information that could pay off later. Neither alone works: pure exploitation locks in early, possibly mediocre habits, while pure exploration never cashes in. Balancing the two—and shifting from more exploration early toward more exploitation as you learn—is one of RL's central, recurring challenges.