You and your various party members can expect to engage in plenty of combat while exploring Genshin Impact. If one of your characters fall in combat and has no more health, you need to revive them so they can assist you in battles. There are specific items you can use in your inventory to bring them back.
Open up your bag and look through the various foods you have for items that revive characters. These will be different than the ones that health your party members, and yourself. Click on the item, give it to the fallen party member, and they should have their icon return with a little bit of health. The first revival item you receive, the Teyvat Fried Egg, only gives back 100 health, so it’s not very much. You have to use other health items to fully restore them before combat.
Alternatively, you can choose to click on the icon or tab number next to their name if you’re playing on a PC to instantly use a revival item. Once they’re ready to go, and healthy, you can return to combat with them and go about your business in Genshin Impact. You want to make sure to have a handful of revival items in bag to make sure you can readily restore any party members who fall in combat.