Health - When this indicator empties you are considered dead and will respawn at a random spawn point.
Stamina - This is an indication of how tired you are. Players with zero Stamina will not be able to run but walking will refill it. The amount of items players are carrying can also affect Stamina.
Hunger - This indicates the players hunger level. Once it has depleted, players will start taking hunger damage which will become fatal if not reversed quickly.
Thirst - This indicates whether or not you are thirsty. Swimming in the water will refresh your thirst (swimming under the water works better but dont stay there long or you may drown), as will drinking juice or another crafted drink. Waterskins can be filled and carried to relieve thirst as well. Players can fill them while it’s raining or while they are swimming.
Oxygen - Indicates the level of breath you have left while swimming. If this depletes, your character will die. Oxygen depletes 3x faster while sprinting in the water.
Temperature - This indicator tells players if they are hot or cold. Above the center is hot, below is cold. Players will receive message warnings when the temperature is at a critical level.
Hotbar - At the bottom of the players screen is a hotbar with 8 hotkeys. Dragging items from the inventory to the hotbar will make them available for use by pressing that key. Right click on any key to remove the icon assigned to it. Pressing the hotkey a second time will remove the item from the player's hand.
Screenshots without the HUD
To remove the HUD from the screen for screenshots, press CTRL-Z. Press it a second time to remove the reticle as well. A third press will return them both to the screen.