You have found the perfect car that you would like to buy. Already agreed on everything with the seller, bargained for a good price. However, he asks to wait a few more days to buy another car for a change. You don't seem to mind, but you're afraid he won't change his mind or change the price. Of course, the seller also asks for a deposit in order to remove the ad for sale.
It is for such cases that there is a preliminary agreement.
This is an agreement in which the parties agree that they will enter into a basic agreement within a specified period on a predetermined terms.
On the example of a car, the parties in the preliminary agreement may agree that 20 days after signing the preliminary agreement, they will enter into a contract of sale of the car. At the same time, they can fix the cost of selling the car and its equipment or any other conditions of sale.
Also, such a contract can determine the consequences of the fact that the seller or buyer will change his mind to enter into the main contract. It may be an obligation to pay a certain amount to the other party as monetary compensation for the inconvenience caused.