API (application programming interface)

An API, or application programming interface, is a set of rules, protocols and tools that enable different software applications to communicate with each other. In other words, an API acts as a bridge between two distinct applications, facilitating their interaction. It acts as an intermediary, translating requests and responses in a way that both systems can understand.

APIs are ubiquitous in every type of application or specialized site. They play an important role in the creation of interconnected software ecosystems. For example, when you use a mobile application for various services such as checking the weather, that application can use an API to retrieve weather data from an external service. Similarly, a flight booking application can interact with the systems of different airlines via their respective APIs, through a request sent to each of them.

There are many different types of APIs. Web APIs, for example, are designed for use over the internet, connecting a user’s device to a web server, and are often based on HTTP or HTTPS protocols. Library APIs, on the other hand, are collections of routines, protocols, and tools for creating and/or modifying software. Operating system APIs enable applications to communicate with the underlying operating system, opening up functionalities such as file access or cloud memory management.

Designing an API is a complex task. Developers need to consider many factors, such as ease of use, flexibility, security, and performance. A good API must be intuitive, well documented, and capable of handling a wide range of usage conditions. It must also be regularly maintained and updated to adapt to user needs and technological advances.

Security is also a major aspect of API design. Data must be protected, using authentication and encryption methods. Usage limits, often called “quotas,” can also be put in place to prevent abuse and ensure reasoned use.

APIs have helped to change the way software is built and deployed, both at the code level on the development side and at the customer experience level on the front end, with greater flexibility. They facilitate the linking of information and accelerate the development of software products. They have also paved the way for new forms of collaboration and partnership between companies and developers.