Business Rules are server-side scripts that run when a record is displayed, inserted, updated, or deleted. The "When" field on the Business Rule form determines exactly when the logic runs relative to the database operation. The four valid options are:
Display: Runs before the form is presented to the user (used to pass data from server to client via the Scratchpad).
Before: Runs after the user submits the form but before the data is written to the database. (Ideal for validation or updating the current record).
After: Runs immediately after the data is written to the database. (Ideal for updating related records).
Async: Runs after the data is written, but is processed by a background scheduler rather than immediately. (Ideal for external integrations or heavy calculations that shouldn't block the user's screen).
"Load," "Change," "Click," and "Submit" are typically associated with Client Scripts (onLoad, onChange, onSubmit) or UI Actions, not Business Rules.