In Hindu mythology, the nectar of immortality produced by churning the ocean is called amrita.
The Samudra Manthana tells how the devas and asuras churned the ocean of milk to obtain divine treasures. Dhanvantari emerged carrying a vessel of amrita, which could restore or preserve immortality. The devas ultimately gained access to it after Vishnu appeared as Mohini and distributed it to them.
Amrita is related linguistically and conceptually to the idea of immortality. In Sanskrit, the word is associated with something deathless or undying. It is often compared with soma, another sacred substance in Hindu tradition, but the two belong to different mythic and ritual contexts.
The churning also released halahala, a deadly poison, before the nectar appeared. Shiva consumed that poison, an event associated with his blue throat.