Unstructured Supplementary Service Data (USSD) is a communication protocol used by mobile network operators to offer real-time interactive communication between users and applications or services. USSD messages can be initiated by dialing a specific code on a mobile phone and are often used to access a wide array of services, check balances, or perform transactions.

Key aspects and applications of USSD include:

Interactive Communication: USSD allows for real-time interactive sessions between users and applications, enabling dynamic communication with menus, prompts, and options.

Service Accessibility: USSD is widely utilized to provide access to various services, such as mobile banking, balance inquiries, mobile top-ups, and information retrieval.

Instantaneous Responses: USSD messages provide immediate responses, making it an efficient channel for obtaining quick information and conducting transactions.

Widespread Usage: USSD is commonly used by mobile operators to offer a broad range of services to their subscribers due to its ease of use and wide accessibility.

USSD is a valuable tool that enhances communication and service accessibility for mobile users, allowing them to interact with applications and services in real time.