A trust is a way to hold assets and money. The main purpose of it is so that you can avoid probate.
If you die without having stuff in a trust, you have to go through probate. It takes a long time, it costs quite a bit of money, it ties up a lot of your assets.
A trust lives on after a person dies. Most of the time when people set up a trust, they just put everything into it. And they start treating the trust as themselves, so you don't lose any rights of all your property.
If I died and I had a checking account in my name, and my bank cares about it, they lock the checking account down. Nobody can get into it.
But if it's in the name of a trust, it'll automatically go to the trustee. They won't lock that bank account.
With a will, when you die, it can take up to 2 or 3 years before your property is disbursed. With a trust, it's instantaneous.