APIs (Application Programming Interface), or app programming interface, are professional digital waiters that allow communication between two apps. APIs can be examined in different aspects and identify different types of them. In this article, we are looking to review and introduce them in different aspects of APIs.
In general, the APIs can be examined in three respects:
- Publishing Policies
- Uses
- Protocols/Architecture
You can see this subdivision in the image below and read the description below.
APIs in terms of publishing policies
APIs can be placed in three categories: Private, Partner and Public.
Private APIs
These APIs are created to improve the strategies and services of an organization. Developers within the organization or contractor of the organization can use these APIs to integrate the company’s information technology systems or applications and build new systems or apps using existing systems. Private APIs allow the company to have complete control over how to use APIs.
Particular APIs
Particular APIs are freely marketed; But only businesses can use the agreement with the API publisher. This agreement could be in the form of a formal contract, a memorandum, or any other commercial and non -commercial agreement. The common use of partnership APIs is software integration between the two sides. The benefits of such APIs for publishers include:
- Utilization
- Monitor how digital assets are used
- Ensure the design of the desired user experience by the user of the API
- Maintaining the company’s identity in apps designed by API users
Public APIs
These APIs, also known as external APIs, are available for any developer and third party. Public APIs, if properly offered, allow the company to raise brand awareness and use a new source of income.
There are two types of public APIs: free (free) APIs and commercial APIs. Open APIs are completely public and can be used without any restrictive conditions. For example, an app can be designed using APIs, without the need to obtain confirmation of the publisher or pay the subscription fee.
Commercial API users pay a fixed subscription to use them or pay for the publisher each time they use these APIs. The conventional approach of publishers towards these APIs is free of limited use so that users can evaluate the APIs before purchasing.
API types in terms of use
APIs can be categorized by the type of systems for which APIs are built.
Database APIs
Database APIs communicate between an app and a database management system. Developers work with databases by writing queries to access data, change tables and other similar actions. For example, The Drupal Database API allows users to write unified queries for different data databases.
Another example is the ORDS database API embedded in Oracle Rest Data Services.
Operating system APIs
This group of APIs defines how apps use the resources and services of the operating system. Each operating system has its own set of APIs (for example, Windows APIs or Linux APIs).
Apple has also released APIs for MacOS and iOS operating systems. These APIs can be examined in Cocoa environment.
Remote APIs
These APIs define standards for engaging apps set up on different devices. In other words, one of the apps accesss the resources outside the device on which it is located. Since the two apps are intertwined through a communication network (usually the Internet), most of the remote APIs, based on web standards, are written. Java Database Connectivity API and Java Remote Method Invocation API are two examples of Remote APIs.
Web APIs
These types of APIs are the most common type of API. Web APIs provide car -readable data and the ability to transfer them through web systems. These APIs usually transfer web applications to servers and servers respond to apps using http protocol.
Developers can use these APIs to develop their applications and websites. For example, the Pinterest API offers a tool to add data on the Pinterest page of users to a website. Or Google Maps API allows the company’s location map to the website.
API protocols
The purpose of the API protocols is to standardize data transfer between web sessions. In this case, standardization means the ability of different systems – written in different programming languages, or run on different agents or are based on different technologies – in relation to each other.
Remote Procedure Call (RPC)
Web APIs may be based on the principles of resource exchange for RPC basis. This protocol defines the interaction between client/server apps. One client requests data or operations from another program (server) located on the other computer on the network, and the server returns the response related to that request.
RPC is also known as a subrotein or function call. One of the two ways to implement RPC is soap.
Service Object Access Protocol (SOAP)
Soap, based on the definition that Microsoft (its main developer) has provided; The Lightweight Protocol is a decentralized and scattered environment for exchanging structured data in the decentralized environment. Overall, this protocol includes Syntax Rules for requests and sending messages by two web applications. APIs that follow the SOAP rules make it possible for XML messaging between systems via HTTP or SMTP.
XML is a simple and very flexible text format used to store and transfer data on the Internet or other networks. XML defines a set of rules for coding documentation in a way that is readable to both human and machine.
SOAP is mainly used for web -based software for large corporations to ensure the high security of transmitted data. SOAP APIs are desirable for provider of payment gateway services, identity management, customer relationship management strategies, and financial and communication services.
RepeSentational State Transfer (REST)
The word REST was introduced by a computer scientist named Roy Fielding in 2000. Unlike SOAP, which is a protocol, REST is a software architectural style for building apps based on HTTP (usually websites).
REST is considered an easier option than SOAP; Because SOAP seems to many programmers, it needs to write many codes to complete a task and follow the XML structure for each message. REST follows another logic because it puts data as sources. Each source is displayed by a unique URL and can request access to that source by providing its URL.
To the woven APIs that follow the restrictions of the rest structure; Restful APIS refers to. These APIs use HTTP requests: Get, Put, Head, Post, Patch, Connect, Trace, Options and Delete.
Restful API supports messenger in different formats, such as simple text, HTML, YAML, XML and JSON; While SOAP only supports XML. The ability to support a variety of formats for storing and transferring data is one of the reasons that REST is a more popular and more popular option these days to build public APIs.
Final speech
In this article, it was attempted to introduce the various aspects of the APIs and to provide a variety of APIs according to these aspects. Understanding and understanding the types of APIs will help you use them better, and with the function of each and the benefits and disadvantages, make more effective decisions about their use.