Minecraft's Nether Update adds a new block to the game called the Respawn Anchor. This block can be used to ensure that the player will respawn at a specific place in the Nether rather than in the Overworld. It works in a similar manner to the Overworld's bed, but is more difficult to manage.
The Nether Update has made some massive changes to the Nether, including the introduction of new mobs like the Piglins and Hoglins and new structures like the Bastion Remnants. In order to better accommodate players wanting to explore these new features, Minecraft has added the Respawn Anchor.
The Respawn Anchor will spawn the player in the Nether even if they die in the Overworld, and replaces the player's spawn point (even one determined by a bed). This makes it very unique, and provides several potential uses for it. Unfortunately, players will need to figure out how to get Crying Obsidian before crafting it.
Crafting a Respawn Anchor requires the player to collect 6 Crying Obsidian and 3 Glowstone. For those wondering, there are three main methods of obtaining Crying Obsidian. The first, and most reliable way, is by trading gold ingots with Piglins, as they will have a ~9.46% chance to gift the player 1 - 3 Crying Obsidian in return. The rare block can also be found in small quantities in chests at the new Bastion Remnants structures in the Nether, or in the overworld at the randomly generating Ruined Nether Portal.
After crafting the Respawn Anchor, the player should place it wherever they'd like to respawn, right clicking it to set their respawn point. Initially, it will be empty, as shown in the first picture, but the player can fill it with Glowstone blocks to charge it by simply using the activate button (Right Click, L2, LT) while holding Glowstone. The Respawn Anchor is capable of holding four charges at a time, and one is expended each time a player dies. It must be refilled constantly, as if the player dies while there are no charges, they will respawn in the Overworld at their starting spawn point.
There are a number of unique uses for this block aside from just regular respawns. Adventure mode map creators could use them as a sort of checkpoint system, and players could even create a central hub in the Nether which connects all of their assets, placing their respawn point there.
Minecraft is available now for Mobile, PC, PS4, Switch, and Xbox One.
Source: Minecraft Wiki