Explanation: What is an API

Explanation: What is an API

The Program Interface for the Application is called the API. In essence, API is a series of functions and procedures that allow applications to access data and other applications, services, and operating systems functionality. Good APIs make it easier to create a computer program by supplying all the components the programmer then compiles. Find below the definition of “What is an API”.

What is an API

Types of APIs

What is an API

Private APIs

These interfaces are intended to enhance an organization’s solutions and services. These APIs may be used by in-house developers or contractors to integrate IT systems or applications in an enterprise, create new systems, or customized applications using existing systems. While applications are freely accessible, only those who work with the API publisher have the interface itself. With the private strategy, an enterprise can monitor the use of the API fully.

Partner APIs

Partner APIs are sold openly but shared with publisher contract partners. Software integration between both parties is the usual case for partner APIs. An organization that allows data access or capacity access to partners benefits from additional revenue streams. In parallel, it monitors the usage of exposed digital assets, ensures that solutions from third parties that use their APIs provide an acceptable user experience, and preserve corporate identity in their applications.

Public APIs

These APIs may be also used by any third-party developer, known as the developer-facing or external. A public API program enables brand recognition and a supplementary revenue stream to be properly implemented.

Public (free) and commercial APIs of two types are available. The Open API Concept ensures that all of the features of such an API are freely accessible. For example, without explicit permission from the API provider or compulsory licensing fees, it is possible to create an application that uses the API. It also says that the API and associated document descriptions must be accessible and free use of the API for applications to be created and tested.

Users of commercial APIs either pay a monthly fee or pay as they go. Free trials are a popular strategy used by publishers to allow users to test APIs before buying subscriptions.

Also Read:- What is Big O Notation Explained: Space and Time Complexity

APIs by use cases

Database APIs

An application can interact with a database management system using database APIs. Developers work with databases to collect data, modify tables, and so on by writing queries. For example, the Drupal 7 Database API enables users to write unified requests for various proprietary and open source databases (Oracle, MongoDB, PostgreSQL, MySQL, CouchDB, and MSSQL).

The ORDS database API, and Oracle REST Data Services component, are another example.

Operating systems APIs

This collection of APIs specifies how applications interact with operating system resources and services. Every operating system has its own collection of APIs, such as the Windows API or the Linux API (kernel–user-space API and kernel internal API), for example.

Apple’s developer guide includes API references for macOS and iOS. The Cocoa package of developer tools includes APIs for creating apps for Apple’s macOS desktop operating system. Cocoa Touch, a tweaked version of Cocoa, is used for those developing applications for the iOS mobile operating system.

Remote APIs

Remote APIs define interaction standards for applications that run on different machines. To put it another way, one software product accesses services that are not located on the computer that is requesting them, which explains the name. Since two remote applications, in particular the Internet, are connected through a communication network, the majority of remote APIs use Web standards. Two examples of remote application programming interfaces are the Java Database Connectivity API and the Java Remote Method Invocation API.

Web APIs

This is the most frequently used API style. Online APIs enable data and functionality to be shared between machine-readable systems with a client-server architecture. The Hypertext Transfer Protocol is used primarily by these APIs to submit web requests and server responses (HTTP).

To boost the functionality of their applications and websites, developers may use Web APIs. In the Pinterest API, for example, you can find tools to integrate Pinterest data in websites like boards and Pins. With the Google Maps API, an organization can be shown on a map.

API protocols

API requirements are designed to standardize data transfer between web services. In this case, standardization refers to the ability of various programs written in different programming languages and/or running on different operating systems or using different technologies to communicate with one another seamlessly.

Remote Procedure Call (RPC)

Based on a Remote Procedure Call, Web APIs can adhere to resource exchange principles. The connection between the client-server applications is described here. One app (client) needs information or functionality on another networked computer (server), with the Server supplying the necessary information.

A subroutine or function call is another name for the RPC. SOAP is one of two ways of calling remote process execution.

Service Object Access Protocol (SOAP)

According to Microsoft, which created SOAP, it is a lightweight protocol for sharing structured information in a decentralized, distributed environment. In general, this specification includes the syntax rules for web application requests and response messages. XML communicating between systems via HTTP or the Simple Mail Transfer Protocol for the transmission of email is available via APIs followed by SOAP Principles.

A simple and extremely flexible text format is the extendable bug language (XML, which is widely used in data storage, Internet, and other network transmissions. XML is a collection of rules that can be understood by humans and computers for encoding documents in a format. The markup language is a symbol set that can be used for the demarcation and identification of various parts of the document. Auto descriptive data object tags are used and readily readable in XML text documents.

What is an API

SOAP is most commonly used to ensure data privacy incorporate web-based applications. SOAP APIs are preferable for payment gateways, identity management, and CRM solutions, as well as for financial and telecommunications networks. PayPal Public APIs are one of the most popular SOAP APIs. It is also used for supporting legacy systems.

Representational State Transfer (REST)

In a dissertation published in 2000, computer scientist Roy Fielding coined the word REST. Unlike SOAP, which is a protocol, REST is a software architectural style that includes six constraints for creating HTTP-based applications, such as web services. The most famous realization and implementation of this architecture style is the World Wide Web.

REST is a simpler alternative to SOAP, which many developers find difficult to use because it needs a large amount of code to complete each task and strict adherence to the XML structure for each message sent. Since it makes data accessible as tools, REST follows a different logic. Each resource is identified by a unique URL, which can be used to make a request for that resource.


The developers looked for other approaches to software architecture because they needed faster feature creation, more effective data loading due to increased mobile adoption, and a large number of clients. First created by Facebook in 2012, GraphQL is a modern REST, which is used for API development by firms such as Shopify, Yelp, GitHub, Coursera, and The NY Times.

The API query language is GraphQL. It allows the client to enter the exact data it needs and simplifies the collection of data from different sources so that the developer can only make a single API request for all the necessary details. GraphQL also features a description of data using a framework type.

What is an API


When we consider APIs not only from the perspective of software development but also from the perspective of business cooperation, they play a much larger role. These resource-exchange machine-readable interfaces are similar to distribution systems that operate behind the scenes and provide the required technical connectivity. API integration is crucial to their business plan, according to more than 60% of participants in the Current State of API Integration 2018 survey. According to the report, APIs will be used by more than half of all companies.

The two key tasks for decision-makers and developers in this regard are to choose an API that meets a company’s unique business needs and to learn how to use it effectively

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