Dying without a will put into place means that you've died "intestate" when you die intestate the intestacy laws in your state determines how your property is distributed after you die.
This includes assets such as real estate, bank accounts, securities, money and other assets you own at the time of your death.
It's always good to get a will in place so you can have your assets and anything else distributed the way you would like it to be distributed upon your death.