There are three CSV files.  In the train.csv file, 'Buy' is the target variable containing values 0 and 1. When Buy = 0, it means that the customer didn't click 'Buy'. When Buy = 1, it means that the customer did click 'Buy'. Each customer is uniquesly identified by 'Id' column in the train.csv and test.csv files. A sample submission file named 'submission.csv' is also provided for reference. This CSV file should contain only two columns - Id and Predicted.