The Seven Elements 
In Genshin Impact and Seven Elements, there exists the seven Elements: Pyro, Hydro, Anemo, Electro, Dendro, Cryo, and Geo. Non-elemental damage is considered Physical.
By combining specific elements together, you're able to trigger Elemental Reactions!
When applying an element to an entity, it will decay over time, so there isn't any "infinite elemental application"!
Elemental Combat 
Main page: Elemental Combat
In Seven Elements, you may infuse your attacks with one of the seven Elements and deal Elemental Damage of that element.
Elemental Reactions 
Main page: Elemental Reactions
When applying an element on a target already afflicted with an element, various Elemental Reactions may be triggered.
Elemental Application Systems 
See also: Elemental Gauge Theory and Internal Cooldown
Elements aren't a binary state of applied or removed, and are rather represented as a certain amount of gauge units. Elements can also only be applied in certain intervals, where elemental damage dealt within the interval only deals elemental damage but does not apply an Element.
