An API is a set of routines, protocols, and tools for building software applications. API specifies how software components should interact. A good API makes it easier to develop a program by providing all the building blocks.
SMS API is used by users to integrate SMS with other Servers or Databases in order to automatically send SMS. SMS API is a script which helps developers to integrate to send and receive SMS flawlessly, but also to create sub accounts and users.
SMS API can be used by schools for sending fee reminder SMS, attendance SMS, and on the other side it can also be used in restaurants, and departmental stores integrated with POS to send transactional SMS.