Introduction:
When it comes to revising for exams, students often wonder whether they should focus on understanding or memorization. Both approaches have their merits, but it is important to strike a balance between the two. In this response, we will explore the benefits of both understanding and memorization in the context of exam preparation.

Understanding:
- Comprehension: Focusing on understanding the concepts allows for a deeper level of comprehension. This involves grasping the underlying principles, connections, and applications of the topic.
- Retention: When you understand a concept, you are more likely to remember it for a longer duration. This is because your brain forms meaningful connections and associations, making it easier to recall information during the exam.
- Application: Understanding a topic enables you to apply the knowledge to real-world scenarios or solve complex problems. This is particularly important in competitive exams like UPSC, where the ability to analyze and apply concepts is tested.

Memorization:
- Recall: Memorizing key facts, formulas, and definitions can aid in quick recall during the exam. Some information simply needs to be memorized, especially in subjects like history or vocabulary-based questions.
- Time management: Memorization can save time during the exam as you do not have to spend additional time thinking about or deriving certain information. This allows you to allocate more time to solve complex problems or write detailed answers.
- Foundation: Memorizing foundational information can provide a solid base upon which you can build your understanding. It can help you grasp more complex concepts as you progress in your studies.

Striking a Balance:
It is crucial to strike a balance between understanding and memorization. Instead of viewing them as opposing strategies, they should be seen as complementary. Here are a few tips to achieve this balance:
- Conceptual clarity: Start by developing a strong understanding of the fundamental concepts. This will provide a solid foundation for further learning and memorization.
- Active learning: Engage in active learning techniques such as summarizing, explaining concepts to others, and solving practice questions. This will reinforce your understanding while also aiding in memorization.
- Flashcards and mnemonics: Use flashcards and mnemonic devices to aid in memorizing important facts, formulas, or vocabulary. These techniques can help in quick recall during exams.
- Regular revision: Regularly revise both the understanding-based concepts and the memorized information to reinforce your knowledge and ensure retention.

Conclusion:
In conclusion, a balanced approach to revision is essential for exam preparation. While understanding forms the basis for comprehension and application of knowledge, memorization aids in quick recall and time management. By combining both strategies and finding the right balance, you can optimize your revision process and increase your chances of success in exams like UPSC.