API (Application Programming Interface): Definition

Summary

• An API (Application Programming Interface) is a standardized set of methods that allows different software programs to communicate without knowing their internal details.
• It functions as a front end between applications, using protocols such as HTTP, REST, or SOAP to structure data exchanges.
• APIs are used in administration (access to government data), finance (banking and fintech services), the web (social networks), and software development.
• They facilitate collaboration between teams, save time by reusing existing features, and simplify the integration of third-party services.
• API Management secures these interfaces and helps manage their lifecycle with reporting tools to monitor their consumption.

What is an API and how does it work?

An API (Application Programming Interface) is a standardized set of classes, methods, functions, and constants. This programming interface allows software to offer services to other software in a structured manner.

An API acts as a facade between applications by defining how programs can interact. It hides the internal details of the system while providing access to its functionality. Developers reuse functionality building blocks without knowing the internal logic of the third-party software.

The technical components of an API include:

• Classes and methods for structuring interactions
• Predefined functions to simplify data access
• Constants to standardize exchanges
• Communication protocols such as HTTP and REST

Service-oriented architecture allows applications to depend on third-party functionality via APIs. This approach facilitates collaboration between development teams and saves time.

The life cycle of an API request follows a simple process. The client application sends a request via the application programming interface. The server processes the request according to the defined access constraints. It then returns the data or confirms the requested action.

APIs use different protocols depending on requirements. REST uses HTTP for simple web exchanges. SOAP offers greater security for complex transactions. These interfaces enable computer systems to communicate effectively without exposing their internal architecture.

Examples of APIs and practical applications in different sectors

Examples of APIs illustrate their usefulness in all areas. Public administrations use APIs to provide access to government data. Citizens consult their tax records via web interfaces connected to internal systems.

Banking APIs are revolutionizing financial services. Fintech applications integrate payment features without developing their own systems. Banks expose their APIs to enable secure access to customer accounts.

On the web, social media APIs facilitate content sharing. Facebook and Twitter provide interfaces that allow third-party sites to integrate their features. Social authentication simplifies user login.

Software development relies heavily on APIs. Libraries and frameworks provide standardized interfaces. The Windows API allows you to create applications that manipulate files, processes, and graphical interfaces. Java EE provides APIs for database and transaction management.

Database APIs enable real-time access to data. Applications query and modify information without knowing the technical details of the storage system.

API Management secures exposed interfaces and facilitates their lifecycle. Reporting tools help manage API consumption. This management constitutes a commercial contract describing the available features and their limitations.

APIs transform digital communication by seamlessly connecting different software applications. By understanding how they work, developers and businesses can optimize technology integration, simplify data exchange, and create innovative solutions that address modern IT challenges.