Introduction to API – How API works

APIs (application programming interfaces) are a big part of the web. In 2013 there were over 10,000 APIs published by companies for open consumption. That is quadruple the number available in 2010.API stands for Application Programming Interface.

An API is essentially a set of rules that dictate how two machines talk to each other. Some examples of API-based interactions include a cloud application communicating with a server, servers pinging each other, or applications interacting with an operating system.

Whenever you use an app on your phone or computer you’re interacting with several different APIs behind the scenes. Nearly all businesses that use any kind of modern technology use APIs at some level to retrieve data or interact with a database for customers to use.

An API’s defined communication protocol is what enables developers to build, connect, and integrate applications quickly and at scale.

Some businesses don’t just employ internal APIs, which their engineers use to build features for their consumers. Many companies also use external APIs, which the developer community uses to launch products. Some examples include Twilio (communications API), Stripe (payments API), and Sendgrid (email API), which offer a “Platform as a Service” (PaaS) model.

Such companies enable developers to build applications on their platform, which might perform functions such as hosting web servers or communication applications. There are businesses whose main value comes from connecting different APIs and web services, which are categorized as “Integration Platform as a Service.” IPaaS companies let users connect disparate web services and tools, most notably to route data or automate workflows. Both of these verticals have grown tremendously, fuelled by the extensibility and ease of use of APIs.

Why API is important in Web Scraping

In Simplest terms API makes data extraction very easy. Many of the large companies offer API for publicly available data extraction So if a website offers you an API for data extraction you should use it, if it gives you the required data. This makes the process legal, safe and extremely easy. Especially for Twitter and Google we recommend to use their API for data extraction as they are simple to use and free for general use.

How API Works

An application programming interface is a set of rules that define how computers, applications, or machines can talk to each other. You can think of it this way: the typical user interface is intended for use by a human being, while APIs are intended for use by an application or computer.

Most web APIs sit between the application and the web server. The user initiates an API call that tells the application to do something, then the application will use an API to ask the web server to do something. The API is the middleman between the application and the web server, and the API call is the request. And every time you use software to communicate with other software or online web servers, you’re using APIs to request the information you need.

It’s important to note that while web APIs are the most common, APIs aren’t limited to the web. There are APIs for virtually every machine or system that expects to interact with other machines or systems.

Types of API

Web APIs

There are four main types of APIs:

Open APIs: Also known as Public API, there are no restrictions to access these types of APIs because they are publicly available.

Partner APIs: A developer needs specific rights or licenses in order to access this type of API because they are not available to the public.

Internal APIs: Also known as Private APIs, only internal systems expose this type of API. These are usually designed for internal use within a company. The company uses this type of API among the different internal teams to be able to improve its products and services.

Composite APIs: This type of API combines different data and service APIs. It is a sequence of tasks that run synchronously as a result of the execution, and not at the request of a task. Its main uses are to speed up the process of execution and improve the performance of the listeners.

Web service APIs

Apart from the main web APIs, there are also web service APIs:

• SOAP
• XML-RPC
• JSON-RPC
• REST

A web service is a system or software that uses an address, i.e., URL on the World Wide Web, to provide access to its services.

That’s all for basic of API. Do try and find some websites which offer API for data extraction.