Typically a lottery runs in one of two ways: with pre-decided winning tickets, or a number that's drawn after the tickets are distributed to decide which ticket (if any) is the winner. In this way, the odds of winning are mostly independent of the number of tickets sold. The prize is usually money.
A raffle works by selling tickets, and then picking exactly one of those tickets to be the winner, making the odds directly dependent on the number of tickets sold. The prize is usually a physical object, and not money (though there are exceptions, e.g., a 50/50 raffle).
Often raffles are sold significantly below expected value. A popular raffle to support a charity is called a 50/50 raffle. This is where the winner of the raffle receives 50% of $YN, and the charity receives the other 50%. Buying a ticket isn't a good financial decision, but it's for a charity, and you can end up winning, so they are popular.
The technical difference, vs a lottery, is that a raffle always has exactly one winner, drawn from all of the entries. In most lotteries, it’s possible for no one to win or several people to share the prize.
Raffle also implies that the event is a smaller, one-off event, usually with non-cash prizes and often for charity. A church might have a raffle to raise money for a new roof, using prizes donated by the parishioners. This is in contrast to lotteries, which are usually run by the government, feature cash prizes, and occur on a fixed schedule.
It's not really about "disposing" the donkey it is about giving other people the chance to win the donkey...that is dead