SNOW

BEFORE : Use before insert/update business rule to do some validation and if validation fails stop form submission Use before insert/update business rule to set values for current record based on some other fields on the form such as calculated field AFTER : Use after insert/update business rule to insert/update data in related list table Use to update information on related objects that need to be displayed immediately, such as GlideRecord queries. ASYNC: Use to update information on related objects that do not need to be displayed immediately, such as calculating metrics and SLAs. Mostly used to call 3rd party SOAP or REST endpoints DISPLAY : Mostly used to send field value from server side to client side; for the fields which are not available on the form, this value can be used in onload, onchange, onsubmit client scripts