Here's a breakdown:
* Formal: In formal settings, "adios" is appropriate for both casual and more serious farewells.
* Informal: It's equally common in informal settings, like among friends or family.
* Emotional: "Adios" can be used to express a sense of finality or sadness, but it can also be used casually.
Note: While "adios" is the most common form, some variations exist:
* "Adiós" with an accent on the "o" is often used in formal writing.
* "Adiós" with an accent on the "i" is less common but still used in certain contexts.
In general, "adios" is a simple and straightforward way to say goodbye in Spanish.