What is a Decision Tree in Machine Learning?

Updated May 16, 2026

Short answer

A Decision Tree is a supervised learning model that splits data into branches based on feature conditions to make predictions.

Deep explanation

A Decision Tree works by recursively splitting the dataset into subsets based on feature values. Each internal node represents a decision based on an attribute, each branch represents an outcome, and each leaf node represents a prediction. The goal is to create homogeneous subsets using metrics like Gini impurity or entropy.

Real-world example

Used in loan approval systems to classify applicants as eligible or not based on income, credit score, and history.

Common mistakes

  • Assuming decision trees always generalize well without pruning.

Follow-up questions

  • What are internal and leaf nodes?
  • Is Decision Tree supervised or unsupervised?

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