A more thorough explanation:

A buy-sell agreement is a legal agreement that limits the ownership rights of closely-held organizations. It requires that when an owner decides to leave or passes away, their shares must be resold to either the organization or current partners. This is done to keep control over who is in the business.

For example, let's say that John and Jane own a small business together. They have a buy-sell agreement in place that states if one of them decides to leave the business, they must sell their shares back to the other partner. This ensures that the remaining partner has control over who is involved in the business.

Buy-sell agreements are common in partnerships and proprietorships where the owners have a lot of control within the business. The owners want to make sure that their stake in the business cannot be given to an untrustworthy person. A buy-sell agreement prevents any form of transferring ownership except back to the business or other owners, even in a will.

Overall, a buy-sell agreement is a way for closely-held organizations to maintain control over who is involved in the business and ensure that ownership stays within trusted individuals.