A will is a testamentary document, often referred to by lawyers as an ‘instrument’, setting out what a person intends to have happen to their property, (real and personal), and other matters, when they die.
It is the legal way to record a person’s instructions and wishes on how they want their property distributed on the event of their death, and who is to responsible for carrying out those wishes.
Because it is to take effect only on death, a will is referred to as being ‘testamentary’.
A testamentary document or instrument is one which its writer intends, at the time of writing it, to come into effect when they die, and not before. It is where a person sets out their intentions for the distribution of their property when they die.