In Norse mythology, the warriors chosen for Odin’s hall are called einherjar.
The einherjar are the battle-dead selected by valkyries and brought to Valhalla. Their name is commonly translated in connection with “those who fight alone” or “the once-fighters,” although translations and etymological explanations vary.
Their afterlife is active rather than restful. The sources describe them fighting during the day and returning for a feast, with the restored boar Sæhrímnir and mead supplied by Heiðrún. Their purpose is to be ready for Ragnarök.
Einherjar should not be used as a general word for every dead person in Norse mythology. It refers specifically to the heroic warriors associated with Odin’s hall, while other dead may be connected with Fólkvangr, Hel, or different destinations.