Introduction:
When it comes to revising Zoology, both online courses and study materials have their own advantages and disadvantages. The choice between the two ultimately depends on an individual's learning style, preferences, and availability of resources. In this response, we will discuss both options in detail to help you make an informed decision.

Online Courses:
Online courses offer a structured approach to learning Zoology and provide a comprehensive understanding of the subject. Here are some key points to consider:

1. Flexibility:
- Online courses provide flexibility in terms of time and location. You can access the course material whenever and wherever it is convenient for you.
- This is especially beneficial for individuals who have other commitments such as work or family responsibilities.

2. Interactive Learning:
- Online courses often include interactive elements such as quizzes, discussions, and multimedia resources, which help in engaging the learners and making the learning process more enjoyable.
- This interactive approach can enhance understanding and retention of the concepts.

3. Expert Guidance:
- Many online courses are taught by subject matter experts who have in-depth knowledge and experience in the field of Zoology.
- Their expertise and guidance can provide valuable insights and clarify any doubts or misconceptions.

4. Updated Content:
- Online courses are regularly updated to incorporate the latest research and discoveries in the field of Zoology.
- This ensures that you have access to the most recent and relevant information.

Study Materials:
Study materials, such as textbooks and reference guides, are traditional resources that have been used for learning for a long time. Here are some points to consider:

1. Cost-effective:
- Study materials are often more cost-effective compared to online courses, as you only need to purchase the required books or resources.
- This can be a significant advantage for individuals on a tight budget.

2. Self-paced Learning:
- With study materials, you have the flexibility to set your own pace of learning.
- You can spend more time on challenging topics and revise as many times as needed without any time constraints.

3. Accessible Offline:
- Study materials do not require an internet connection, making them accessible even in areas with limited or no internet access.
- This can be beneficial for individuals who prefer studying in offline environments or have limited internet connectivity.

4. Personalized Approach:
- Study materials allow you to personalize your learning experience by focusing on specific topics or chapters that you find more challenging or interesting.
- This can help in better understanding and retention of the concepts.

Conclusion:
Ultimately, whether you choose online courses or study materials to revise Zoology depends on your individual preferences, learning style, and availability of resources. Online courses provide a structured approach, interactive learning, expert guidance, and updated content, while study materials offer cost-effectiveness, self-paced learning, offline accessibility, and a personalized approach. Consider your specific needs and choose the option that aligns with your learning style and goals. Remember, consistency and regular revision are key to mastering Zoology, regardless of the method you choose.