Web API Introduction and Types

Introduction to Web API

If you're a beginner, even the thought of APIs is a little scary.What kind of dark magic is that?And why everyone pays API developers hundreds of thousands.Do they drink blood and offer sacrifices around the flock in the moonlight?

Soon, when those cool kids claim to be inventing calculus, you're out of the loop and feel like Andy below.If you identify with it, you are lucky.We're talking about APIs.

What is an API?

API is short for Aapplication Programming Interface, but no one calls it that, any more than no one calls USB Universal Serial Bridge.The technical meaning of an API is that it is a set of definitions and protocols for building, communicating, and integrating application software, hence the name "interface".

But technical jargon aside, an API is just a way to interact with an application and its inner workings are invisible to external users.APIs allow external users (clients) to "request" something from an application or server and get a corresponding "response".

In fact, you're already using the equivalent of a real-world API.For example, take an old-fashioned taxi.To get a taxi, you will need:

1. “Request”: Request a taxi to pick you up with your contact and location information

2. "Response": In the "Response" to your request, you will get the details of the taxi and the taxi will come and pick you up.

3. You again "request" ( "Request" ) the taxi driver to take you to a specific location.

4. In "Response" ("Response"), the taxi driver takes you to the place you want.

Now you don't need to know how to operate a car to get from one place to another, taxi drivers are like an API.You may know nothing about the operation of the car, but you can interact with the API layer, which is the driver, and navigate to the results you want.

Another way to look at an API is that it's a magic box that takes input in a very specific format and gives output in a very specific format.This "normalization" of input and output (I/O) is useful in application development, making it easy for developers to interact with systems they do not control.

Type of API

If you've heard the term API, chances are it's used to refer to a very specific type of API called Web API.In general, however, the term API may have other meanings depending on the purpose of the API.

According to the purpose, APIs can be roughly divided into the following four categories:

1. Web APIs are used to communicate between servers and clients over the Internet.Web APIs, as the name suggests, are a very specific type of API for interacting and manipulating information or resources on the Internet.
2. Remote APIs define interaction standards for applications running on different machines.For example, connect a database to a program's JDBC connection API.
3. Libraries and frameworks serve as interfaces to software and are also a type of API.
4. The operating system can specify APIs for applications to interact with the device.For example, an Android device with a camera needs an OS API to enable any application to control the camera.