When we talk about API , we mean Application Programming Interface (Application Programming Interface). APIs allow different software applications to communicate and interact with each other. It defines a set of regulations and protocols used to determine the format, method and function of data transfers and requests.
The role of an API is to provide an easy way to share and use functionality or data in software development. By using an API, developers can leverage the functionality of other applications or services without writing the entire code from scratch. APIs allow applications to access remote servers, send requests and receive responses, fetch and process data, and more.
APIs are usually based on specific protocols, such as HTTP (for Web development), SOAP (for Web services), RESTful (a Web service architecture based on HTTP protocol), etc. Different APIs have different functions and purposes, such as accessing data of third-party services, invoking methods of remote servers, performing specific operations, and so on.
APIs are usually provided in the form of documents, which contain detailed information such as API usage instructions, request formats, parameters, and returned data. Developers can understand how to use the API correctly based on these documents, and integrate and call the API in their own applications. You may have seen the full English name of API (Application Programming Interface) in many books. WIN32 API is the application programming interface of Microsoft Windows 32-bit platform . The understanding of this definition needs to be traced back to the development history of the operating system. When the WINDOWS operating system began to dominate, developing applications under the WINDOWS platform became a need for people. However, in the initial stage of development in the field of WINDOWS programming , the only programming tools that WINDOWS programmers can use are API functions. These functions are the interfaces provided by WINDOWS to applications and operating systems. A variety of applications with rich interfaces and flexible functions. Therefore, it can be considered that the API function is the cornerstone of the entire WINDOWS framework. Below it is the core of the WINDOWS operating system, and above it are all gorgeous WINDOWS applications. However, WINDOWS program development at that time was still relatively complicated work. Programmers had to memorize a lot of commonly used API functions, and had to have an in-depth understanding of the WINDOWS operating system. However, with the continuous development of software technology, many excellent visual programming environments have emerged on the WINDOWS platform. Programmers can use the "what you see is what you get" programming method to develop applications with beautiful user interfaces and powerful functions. These excellent visual programming environments are easy to operate and have a friendly interface (such as VB, VC++, DELPHI, etc.), a large number of class libraries and various controls are provided in these tools, which replace the mysterious functions of the API. In fact, these class libraries and controls are all based on WIN32 API functions. A collection of API functions. They combine commonly used API functions into a control or class library, and endow it with convenient methods of use, thus greatly accelerating the process of WINDOWS application development. With these controls and class libraries, programmers can focus on the design of the overall function of the program without paying too much attention to technical details. In fact, if we want to develop more flexible, practical, and efficient applications, it must involve the direct use of API functions. Although class libraries and controls make the development of applications much easier, they only provide the general functions of WINDOWS. Functions, for more complex and special functions, it is very difficult to implement using class libraries and controls, and API functions are required to implement them.