| Lead | A contact in a list: one person, one or more phone numbers, custom fields |
| Attempt | One call or one message to a lead, with its own outcome |
| Disposition | The call outcome an agent picks; it decides what happens to the lead |
| Overdial | Dialing more numbers than there are free agents, expecting that not everyone answers |
| Abandon / wait | A person who answered did not get an agent in time: waited longer than normal, hung up, or reached the ceiling |
| Missed-wait target | The share of answered calls allowed to wait longer than normal (abandonTargetPct, 3 % by default); the pacer steers by it |
| Customer-first | Call the customer first, find an agent after they answer (power, predictive) |
| Agent-first | Take the agent and put them in the conference first, then call the customer (preview, progressive, callbacks) |
| AMD | Answering Machine Detection: Twilio decides whether a person or a machine answered |
| CPS | Calls per second: the rate of new calls a Twilio account may place |
| DNC | Do Not Call: numbers that must not be called or messaged |
| Calling window | Days and hours when a lead may be contacted, in the lead's time zone |
| Contact-center calendar | The centre's working hours, holidays and events; when linked, the campaign contacts nobody while it is closed |
| Wrap-up | Time after a call when the agent fills in the disposition and notes |
| Callback | A promise to call a lead back at a set time, for any agent or for one agent |
| Sender pool | A set of Twilio senders with channel priority; needed for WhatsApp to SMS fallback |