With a SMS API you can send bulk SMS in a variety of formats and on a range of networks. Available as HTTP (Hypertext Transfer Protocol) or HTTPS (HTTP secure), an API connects a website or application with a SMS gateway. SMS gateways are telecommunication channels that are used for sending and receiving Short Message Service (SMS).
An SMS gateway acts as a relay between the mobile network operators and a wireless applications service provider. These SMS gateways allow for SMS traffic to distributed via a direct connection to the SMSC (Short Message Service Centre) of a mobile network operation and then onto a recipient’s mobile phone number.