A more thorough explanation:

Definition: A key person is an important officer or employee who is primarily responsible for a business's success. They are also known as a key man.

Example: John is the CEO of a successful tech company. He has been with the company since its inception and has played a crucial role in its growth and success. He is considered a key person because his leadership and expertise are essential to the company's continued success.

Explanation: In this example, John is the key person because he is the CEO and has been instrumental in the company's success. If he were to leave the company, it could have a significant impact on the business's operations and profitability. Therefore, it is important for the company to have a plan in place to mitigate the risk of losing a key person.