A more thorough explanation:

Definition: A casebook is a collection of extracts from instructive cases on a specific subject. It usually includes commentary and questions about the cases, designed as a teaching aid. The casebook is used to help students learn about a particular subject by analyzing real-life examples.

Example: A law professor might use a casebook to teach their students about contract law. The casebook would include extracts from real cases that deal with contract law, along with commentary and questions to help the students understand the legal principles involved.

Another example: A medical school might use a casebook to teach their students about diagnosing and treating a particular disease. The casebook would include real-life examples of patients with the disease, along with commentary and questions to help the students understand the best practices for treating the disease.

These examples illustrate how a casebook can be used as a teaching aid to help students learn about a particular subject by analyzing real-life examples. The casebook provides a way for students to apply the knowledge they have learned in class to real-world situations.