In a machine learning model, the target variable can be a category variable or a continuous variable. The type of target variable determines what type of supervised machine learning model we have. Fundamentally, we have two types of supervised machine learning models:

• Classifiers: If the target variable is a category variable, the machine learning model is called a classifier. Classifiers can be used to answer the following type of business questions:
  • Is this abnormal tissue growth a malignant tumor?
  • Based on the current weather conditions, will it rain tomorrow?
  • Based on the profile of a particular applicant, should their mortgage application be approved?
• Regressors: If the target variable is a continuous variable, we train a regressor. Regressors can be used to answer the following types of business questions:
  • Based on the current weather condition, how much will it rain tomorrow?
  • What will the price of a particular home be with given characteristics?

Let's look at both classifiers and regressors in more detail.