Long codes are normal individual ten-digit phone numbers from where you can send
sms messages to your customers. You can buy a new phone number directly from the
twilio console.
Short code are shorter six-digit phone numbers, designed for high throughput
two-way messaging. Sending more than a few hundred messages from a long code
risk running into spam. Short codes are not filtered out by carriers and hence
ideal for sending time-sensitive, high throughput messages.
You can buy a short code from twilio
or
migrate an existing one onto twilio.
Messaging Service is a bundle of messaging functionality around a common set of
senders, features, and configuration. It helps you organize your messaging to
fit a specific category of usecases for better tracking and monitoring. Once the
messaging service is created, add one or more long codes/short codes to the
service using the twilio console. Twilio will choose one of the configured
numbers for messaging.
Alpha numeric sender ids in twilio allow you to send messages using an
alphanumeric ID (for example, CASTLED) instead of a standard E.164 formatted
Twilio Phone number. This is mostly used by businesses for higher message
deliverablity, increased open rates and improved brand recognition. Alpha
numeric sender ids are supported only in a few countries.