| Account SID | A unique identifier for a Twilio account. |
| API | Application Programming Interface, a set of functions that allows applications to interact with each other or with other services. |
| Auth Token | A secret key used alongside the Account SID to authenticate API requests. |
| Callback URL | A URL where Twilio sends HTTP requests to deliver event notifications. |
| Carrier | A telecommunications provider that operates phone networks (e.g., AT&T, Verizon). |
| Dial | To initiate a phone call to a specified number. |
| Elastic SIP Trunking | A Twilio service that provides SIP trunking with built-in resiliency, scalability, and global reach. |
| E.164 | An international standard for formatting phone numbers as a string of digits prefixed with a "+" and country code. |
| Friendly Name | A human-readable label for identifying resources, such as phone numbers, within Twilio. |
| HTTPS | Hypertext Transfer Protocol Secure, an encrypted version of HTTP. |
| IVR (Interactive Voice Response) | A system that allows callers to interact with a company’s phone system through voice or DTMF tones to route calls or provide information. |
| JSON | JavaScript Object Notation, a lightweight data-interchange format that’s easy for humans to read and write. |
| Latency | The time it takes for data to travel from the source to the destination, affecting the speed of calls or messages. |
| Long Code | A 10-digit phone number used for person-to-person communication. |
| MFA (Multi-Factor Authentication) | A security process that requires two or more methods of verification for access. |
| MMS | Multimedia Messaging Service, a protocol for sending messages that include multimedia (images, audio, video). |
| Phone Number | A number formatted in compliance with international E.164 standards, used to send/receive calls or messages. |
| REST API | Representational State Transfer API, a design pattern for scalable and stateless web services. |
| SIP | Session Initiation Protocol, a signaling protocol used for initiating, maintaining, and terminating real-time communications such as voice and video calls. |
| SMS | Short Message Service, a protocol for sending text-only messages up to 160 characters long. |
| Short Code | A 5-6 digit number used for high-throughput messaging, often for marketing or alerts. |
| Subaccount | |
| TwiML | Twilio Markup Language, an XML-based language used to control call and messaging behavior in Twilio applications. |
| Two-factor Authentication (2FA) | A security process that requires two forms of identification for access. |
| URL | Uniform Resource Locator, the address for accessing resources on the internet. |
| Voice API | A Twilio API that enables developers to make, receive, and monitor phone calls programmatically. |
| VoIP (Voice over Internet Protocol) | A technology that enables voice communication over the internet. |
| Webhook | A user-defined HTTP callback that sends data to a specified URL when certain events occur. |
| Workflow | A customizable sequence of actions that manage the flow of work in applications, especially in Twilio’s TaskRouter for handling support or contact center tasks. |
| SID | A String Identifier (SID) is a unique key that identifies specific resources. |
| Short Message Peer-to-Peer (SMPP) | A protocol used by the telecommunications industry to exchange SMS messages between short message service centers and/or external systems. |
| Programmable Messaging | Twilio's messaging platform allowing users to send SMS, MMS, and WhatsApp messages from their applications. |
| TaskRouter | Twilio’s service for managing tasks and routing them to the right people or resources based on customizable rules. |
| Twilio Client SDK | A Twilio SDK that allows developers to embed voice or video communication within web and mobile applications. |
