Triggers are conditions that determine whether the bot should execute the current skill or not.
If the trigger conditions of the skill are validated, the bot will execute it over other skills.
If a skill has no triggers, it will never be executed by a user input, but only if it is at the end of a redirection by another skill.
Skills with the fallback type do not have triggers, as they are automatically triggered when no other skill is, or when an error occurs (like if two skills are triggered at the same time).
Note that you can have only one fallback skill per builder.