Reinforcement Learning (RL) is a type of machine learning where an agent learns to make decisions by performing actions in an environment to achieve a goal. This guide will provide an overview of the basics of reinforcement learning.

Key Concepts

  • Agent: The decision-making entity that interacts with the environment.
  • Environment: The external system where the agent performs actions.
  • State: The current situation or condition of the environment.
  • Action: A decision made by the agent.
  • Reward: A signal from the environment that indicates how well the agent performed.

Types of Reinforcement Learning

  • Tabular RL: The agent has a finite set of states and actions, and the state-action value function is stored in a table.
  • Model-Free RL: The agent learns from experience without having a model of the environment.
  • Model-Based RL: The agent has a model of the environment and uses it to make decisions.

Learning Algorithms

  • Q-Learning: An algorithm that learns the optimal policy by estimating the expected future rewards of each action.
  • Sarsa: A variant of Q-Learning that considers the actual reward received after taking an action.
  • Deep Q-Network (DQN): A deep learning approach that uses a neural network to approximate the Q-function.

Example

To understand reinforcement learning better, let's consider a classic example: playing a game of chess.

  • Agent: The computer playing the game.
  • Environment: The chessboard.
  • State: The current position of the pieces on the board.
  • Action: Moving a piece to a new position.
  • Reward: The score of the game after each move.

The computer learns to play chess by exploring different moves and learning from the outcomes.

More Information

For a deeper understanding of reinforcement learning, we recommend checking out our comprehensive guide on Reinforcement Learning Algorithms.

[center] Chess Board