The three Norns in Norse mythology decide the life course and length for every single being.
The Norns have a very important task, and that is to help Yggdrasil stay green and healthy, each morning they carry water from the well Urðarbrunnr and collect the moist earth or clay that lies around the well and pour it over the tree of life Yggdrasil. If they should fail to do this daily task, then the ash tree will start to rot.
The Norns are not goddesses, in fact, they are not even Aesir. They can be described as beings of time. They are the personifications of the past, the present, and the future.
According to the Prose Edda by Snorri Sturluson, the names of this trio of Norns are Urðr, which means “what once was”, Verðandi “what is coming into being”, and Skuld “what shall be".