In order to communicate with machines, we need to know how which interface is working within. Interfaces relating to the mobile application interface and software interface. Whereas one makes the interface by coding with a particular language and develops the interface as per requirement. Innovative interfaces require more innovative ideas towards application interfaces. Command-line interface relates to the programmer that which type of interface we are using to communicate through coding. Whereas natural language interface allows users to speak or type in normal language in order to interact with the computer.