API – Application Programming Interface
(API) stands for Application Programming Interface. In the context of software development, the word Application refers to any software with a distinct function. Interface can be thought of as a set of definitions and rules governing the communication between two applications. For example, If party A’s application sends a remote request structured in a particular way, this is how party B’s application will respond. APIs let your application or service communicate with other products and services without having to know how they’re implemented. This simplifies app development, saves time and money.
Here are some common API use cases and their examples:
1) – Access data from third parties:
In the weather app on iPhone, Apple uses the API of a third party to retrieve weather predictions instead of putting temperature sensors all over the world. You can see on the left-down corner of the surface, Apple is using the API of The Weather Channel.
2) – Security:
When you download a new app, it may ask you does it has access to your location. This is not from the app, instead the system trying to protect your private data. The permission is centralized in the system, and there is no way around it.
3) – Hide complexity and perform tasks:
The operating system provides a bunch of APIs that simplify all of the task for developers, then instead of building everything from scratch (such as connecting to WIFI, designing user surfaces, talking to sensors…), they can focus on the most matter functions.
4) – Extend functionality:
On iOS, applications show a widget in Notification Center. The app notifies the system through an API that it has a widget available. If the user adds a widget to their Notification Center, the system will contact the app to ask how it should display the widget.