What does it mean to call api?

API (Application Programming Interface) is a program interface that allows different applications to interact and communicate with each other. Calling API is to use the interface provided by API to access specific functions and services. These services can be provided by remote data or other applications, or by the operating system itself. For developers, calling API can help them realize the required functions more quickly and efficiently.

Before using the API, we need to know the purpose and services provided by this API. The call format and usage method of API also need to follow the provisions of API documents. Usually, before using the services provided by API, we need to use API keys or tokens for authentication. Various abnormal situations may be encountered during API calling, and we need to deal with them according to the error codes and descriptions provided by API documents.

In our daily life, many applications need to call API. For example, in mobile applications, we may call the weather API to get the weather forecast information of the current city; In social media applications, we may call the API of WeChat or QQ to realize login, message sending and other functions. In e-commerce applications, we can call Alipay or WeChat payment API to realize online payment function. Generally speaking, API calls can help us realize rich functions faster and more efficiently, and improve the user experience of the application.