Genshin Impact is an single-playert open world action RPG developed by the Chinese company MiHoJo.
As a player you are able to have 4 different characters in your party that you can choose and switch to play as.
Every Character has it's own unique elemental abilities. Though there are 7 different elements in the game, every character can only have one varying in Anemo, Geo, Electro, Dendro, Hydro, Pyro or Cryo.
Not only you, but even mobs can have one of the 7 elements.
Depending on your element and the elements of your surroundings, You are able to afflict elemental effects, some of which can cause a debuff.