If you die without a will, your loved ones may be left with no choice but to apply to the court for letters of administration. The court will then decide how your estate will be divided up among your heirs. That division will be done in accordance with the laws of succession that govern in your area, and it may not be the way you would have distributed your property if you had had any say in the matter.
If you want to be the one who makes those decisions, you must make a properly executed will before you die. Your Last Will and Testament will then dictate who the beneficiaries of your estate will be, and how much of your estate each of them will receive.