4. Model, training, inference and features
These four terms are fundamental.
Feature: An input value used to make a prediction.
For customer-churn prediction, features might include:
- Account age
- Monthly amount
- Number of complaints
- Days since last login
Label: The correct historical outcome we want the system to learn.
Churned = true or false
Training: The process that uses historical examples to find useful patterns.
Model: The learned mathematical representation of those patterns.
Inference: Using the trained model to make a prediction for new input.
You train occasionally, but inference may happen thousands of times per minute.