One of the most common and dreaded interview questions, this question is asked so the interviewer can gain insight into your self-awareness, communication, and problem-solving skills. They are also interested in knowing how you perceive and handle challenges. It helps the interviewer to understand if you are willing to acknowledge areas where you need to improve and your ability to work on those weaknesses.
One effective way to answer the question is to be honest and show you are human and have weaknesses like everyone else. It's important to choose a weakness that is not critical to the job you are applying for and to explain how you are working on improving that weakness. For example, you could say "I tend to be a perfectionist and sometimes get caught up in the details, but I am actively working on prioritizing tasks and delegating when necessary to improve my efficiency and time management skills." This shows that you are aware of your weaknesses and are actively taking steps to address them.