One split matters
Your model learns from features and tries to predict one label. In scikit-learn code, features are usually named X and the label is usually named y.
X must not contain the answer column. If it does, your model may look perfect in college demo day and fail on real data.
Features and label
A feature is an input column. Example: hours_studied, attendance_percent, past_score. A label is the target column. Example: pass_fail.
For a builder project, write this clearly in your README later: “I used these columns as features, and this column as the label.”