Virtual long numbers and short codes are the main methods that enable 2-Way SMS. Virtual long numbers are typical mobile numbers provided by mobile operators; they work internationally and when roaming. Short codes are 5-6 digit numbers which are easier to remember and have a national reach. Both virtual long numbers and short codes give enterprises a number they can use to receive and send SMS messages.
A lead keyword is the most basic keyword, here internally a static response is mapped against the given keyword, which is sent when that specific keyword is found at the beginning of the received message.
Poll keywords are used for running polls, where reply messages can be sent using the short message service. You can dynamically set the number of options, and the summary of poll results is dynamically updated on receipt of each message.
URL Based keywords are the most advanced features of all, here we can feed in a custom URL on which a received message is to be forwarded, and response returned will be sent back to the mobile user who sent the message, thus providing a way to plug in our own business logic for such keywords.