Fact-checked May 20, 2026
Also called: RL
Reinforcement Learning (RL) is a type of machine learning where an AI learns to make decisions by trying things out and getting rewards or penalties.
Reinforcement Learning, often shortened to RL, is a powerful approach in artificial intelligence where an agent learns how to behave in an environment to maximize a cumulative reward. Instead of being explicitly told what to do (like in supervised learning), the agent discovers optimal behavior through trial and error, much like how a pet learns tricks through positive reinforcement. Think of a dog learning to sit, it tries different actions, and when it sits, it gets a treat, reinforcing that specific behavior.
The core idea involves an agent, an environment, actions, states, and rewards. The agent performs an action in a given state of the environment, which then transitions to a new state and provides a reward (or penalty). The agent's goal is to learn a 'policy', which is a strategy that maps states to actions, to achieve the highest possible total reward over time.
RL has been successfully applied to a wide range of tasks, including training AI to play complex games like Chess and Go (famously AlphaGo), controlling robotic systems, optimizing industrial processes, and even in personalized recommendations. It's a key component in developing truly autonomous systems that can adapt and learn on their own.
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