Your will lets you decide what happens to your money, property and possessions after your death. If you make a will you can also make sure you can leave in a piece down.
You can write your will yourself, but you can also get legal advice, for example from Government Agency or legal firm to make sure your will is interpreted in the way you wanted.
You need to get your will formally witnessed and signed to make it legally valid.
If you want to update your will, you need to make an official alteration (called a codicil) or make a new will.
If you die without a will, the law says who gets what.