SMS glossary

SMS gateway: A service that connects your application or portal to mobile network operators so SMS can be sent and tracked.
SMS API: A programmatic HTTP interface (at VeloBotix, REST with Basic Auth) to send SMS and check balance.
OTP SMS: A one-time password delivered by SMS for login or verification. The app generates the code; the gateway delivers it.
Transactional SMS: Event-driven messages such as orders, bookings and account alerts — not marketing blasts.
Bulk SMS: One-to-many campaigns, often from CSV or a contact list, with optional personalization.
Sender ID: The name or number shown as the sender. Brand names (alphanumeric) must be registered with operators.
DLR: Delivery report / receipt indicating whether the operator accepted or delivered the message.
Unicode SMS: Messages with Sinhala, Tamil or emoji. They use a shorter character limit per credit than GSM-7 English.