Spawn

The World Spawn Point is where players appear in a newly created world or when joining a multiplayer server. The world's spawn point will be on a surface within five blocks of the horizontal middle of the world. It will almost always be located in the Forest biome as more hazardous biomes cannot appear at the world's center.

A player's Spawn Point is initially the world spawn point, but can be changed by crafting a Bed, placing it in a house and pressing the button on it. The spawn point is where players respawn after dying, and where a Magic/Ice Mirror or Recall Potion will teleport them. Once the house the Bed is in is broken or is pressed on the Bed a second time, the player's spawn point reverts back to the world's initial spawn point.

The world's spawn point is marked by a green arrow icon on the minimap, and the player's spawn point is marked by a  bed icon.

Tips

 * It might be useful to build a shelter over the world spawn point so that the player is provided a minimum of safety if they happen to respawn at the world spawn point, like when the set spawn point is inadvertently reverted back to the initial world spawn point. Similarly, it should be avoided to dig directly underneath the world spawn point, as players respawning there will inevitably fall down.
 * It is possible, albeit extremely rare, for the player to spawn on a Floating Island. In this case, it is highly advisable to use the available blocks to create a staircase to the ground. If there happens to be a Lucky Horseshoe or  Fledgling Wings in the Skyware Chest, then equipping that item allows jumping down without taking fall damage.  Alternatively, one could also generate a new world.