Signals huma l-implementazzjoni ta' Django tal-observer pattern — jippermettu lil ċerti senders jnotifikaw sett ta' receivers meta jseħħu events speċifiċi (bħal mudell li jinħifef jew jinħasad). Jippermettulna decoupled code: parti waħda tal-app tirreaġixxi għal events f'waħda oħra mingħajr coupling dirett.
Common built-in signals
pre_save / post_save → before / after a model instance is saved
pre_delete / post_delete → before / after a model instance is deleted
m2m_changed → a ManyToMany relationship changed
request_started / finished→ request lifecycle
user_logged_in / out → authentication events
