What is API and why it is used?

API is the acronym for Application Programming Interface, which is a software intermediary that allows two applications to talk to each other. Each time you use an app like Facebook, send an instant message, or check the weather on your phone, you’re using an API.

An application programming interface, is a computing interface that defines interactions between multiple software intermediaries. It defines the kinds of calls or requests that can be made, how to make them, the data formats that should be used, the conventions to follow

Different types of Application Program Interfaces (APIs)

There are many businesses today that are migrating from static web presence to more dynamic systems. Even consumers are expecting the data to be readily available at their convenience through devices like smartphones, tabs, game consoles etc. This has increased the importance of APIs (Application Programming Interface) in building dynamic applications for enterprise computing and web services. There are many APIs available today that allow easy integration of applications to legacy systems and enable programs to use each other’s functionality. With various APIs available that are able to offer different features and functionalities, it is important to choose a right one that addresses the business and technical needs of an application or program.

API models – Public & Private APIs

APIs are broadly divided into internal and external based on how they are adopted and shared in a system. Internal APIs are exclusively meant for building internal applications to use within the company or organization or customize it for partners to facilitate service oriented architectures. Using private or internal APIs, organizations can streamline business process and integrate their internal applications across their customers and partners. Contrary to that, public APIs are for open sharing and accessing of information and services. This is like an open resource where the users can create their own unique functionality by extending the original source. Partner API model is another type where businesses work together in a strategic partnership to share data or a service. In this case, businesses that offer API service allow third party partners to embed the service or data into their applications. 

API Types 

Based on how systems or software interact with one another in building the application architecture, there are several APIs available for web service, hardware, operating systems, data structures, programmatic interfaces etc. Some of the standard API class libraries and frameworks are specifically helpful in performing specific actions and exchange of information. For instance, by including or integrating a Javascript Google Maps API in the code, developers can add the feature of interactive Google Maps to an application or a web page. Another example is a YouTube Data API. Using this API, developers can include YouTube functionality to the site to retrieve and manipulate resources like videos, playlists, and channels.

What are Web APIs?

Among several API types, web APIs are widely used to integrate softwares or a service in a website or app through World Wide Web. That means through HTTP protocol the exchange of data or information occurs between desktop, mobile and web applications. Depending on the data transfer formats used in request-response messaging, web APIs are classified as SOAP (Simple Object Access Protocol), RPC (Remote Procedure Call), and REST (Representational State Transfer). These are the different protocols through which exchange of information takes place over web. The most common data formats used to define the response / request messages are XML, JSON, HTML or binary files for documents, videos and images. 

The web APIs are further divided into client and server side based on how they extend their functionality in web browser. Client side APIs are broadly used for manipulating different aspects of browser whereas server side APIs are meant for executing functionality on a server before the data is sent to browser. When a request is made to an API, the result will be in the form of response invoking an action. But there are some special server side APIs called webhooks that act as user-defined HTTP callbacks to invoke a behaviour or event. By configuring an event in one website, an action can be automatically invoked in the other. That means whenever the condition is met in the source site, webhooks acknowledge the event, and triggers the action on the url specified in the form of HTTP request. Today, webhooks are widely used for passing the information or triggering specific events between applications and servers.

Private APIs. These application software interfaces are designed for improving solutions and services within an organization. In-house developers or contractors may use these APIs to integrate a company’s IT systems or applications, build new systems or customer-facing apps leveraging existing systems. Even if apps are publicly available, the interface itself remains available only for those working directly with the API publisher. The private strategy allows a company to fully control the API usage.

Partner APIs. Partner APIs are openly promoted but shared with business partners who have signed an agreement with the publisher. The common use case for partner APIs is software integration between two parties. A company that grants partners with access to data or capability benefits from extra revenue streams. At the same time, it can monitor how the exposed digital assets are used, ensure whether third-party solutions using their APIs provide decent user experience, and maintain corporate identity in their apps.

Public APIs. Also known as developer-facing or external, these APIs are available for any third-party developers. A public API program allows for increasing brand awareness and receiving an additional source of income when properly executed.

There are two types of public APIs – open (free of charge) and commercial ones. The open API definition suggests that all features of such an API are public and can be used without restrictive terms and conditions. For instance, it’s possible to build an application that utilizes the API without explicit approval from the API supplier or mandatory licensing fees. The definition also states that the API description and any related documentation must be openly available, and that the API can be freely used to create and test applications.

Commercial API users pay subscription fees or use APIs on a pay-as-you-go basis. A popular approach among publishers is to offer free trials, so users can evaluate APIs before purchasing subscriptions.

APIs by use cases

APIs can be classified according to the systems for which they are designed.

Database APIs. Database APIs enable communication between an application and a database management system. Developers work with databases by writing queries to access data, change tables, etc. The Drupal 7 Database Api for example, allows users to write unified queries for different databases, both proprietary and opensource (Oracle, MongoDB, PostgreSQL, MySQL, CouchDB, and MSSQL).

Another example is ORDS Database API which is embedded into Oracle REST Data Services.

Operating systems APIs. This group of APIs defines how applications use the resources and services of operating systems. Every OS has its set of APIs, for instance, Windows API or Linux API Kernel user space API and kernel internal API).

Apple provides API reference for macOS and iOS in its developer documentation. APIs for building applications for Apple’s macOS desktop operating system are included in the Cocoa set of developer tools. Those building apps for the iOS mobile operating system use Cocoa Touch – a modified version of Cocoa.

Remote APIs. Remote APIs define standards of interaction for applications running on different machines. In other words, one software product accesses resources located outside the device that requests them, which explains the name. Since two remotely located applications are connected over a communications network, particularly the internet, most remote APIs are written based on web standards. Java Database Connectivity API and Java Remote Method invocation API are two examples of remote application programming interfaces.

Web APIs. This API class is the most common. Web APIs provide machine-readable data and functionality transfer between web-based systems which represent client server architecture These APIs mainly deliver requests from web applications and responses from servers using Hypertext Transfer Protocol (HTTP).

Developers can use web APIs to extend the functionality of their apps or sites. For instance, the Pinterest API comes with tools for adding users’ Pinterest data like boards or Pins to a website. Google Maps API enables the addition of a map with an organization’s location.


Application programming interfaces consist of two components:

  • Technical specification describing the data exchange options between solutions with the specification done in the form of a request for processing and data delivery protocols
  • Software interface written to the specification that represents it

The software that needs to access information (i.e., X hotel room rates for certain dates) or functionality (i.e., a route from point A to point B on a map based on a user’s location) from another software, calls its API while specifying the requirements of how data/functionality must be provided. The other software returns data/functionality requested by the former application.

And the interface by which these two applications communicate is what the API specifies.

The Red Hat specialists note that APIs are sometimes considered contracts, where documentation is an agreement between the parties: “If party first sends a remote request structured a particular way, this is how the second party’s software will respond.” The API documentation is a manual for developers that includes all necessary information on how to work with the API and use the services it provides. We will talk more about the documentation in one of the next sections.

Each API contains and is implemented by function calls – language statements that request software to perform particular actions and services. Function calls are phrases composed of verbs and nouns, for example:

  • Start or finish a session
  • Get amenities for a single room type
  • Restore or retrieve objects from a server.

Function calls are described in the API documentation.

APIs serve numerous purposes. Generally, they can simplify and speed up software development. Developers can add functionality (i.e., recommender engine, accommodation booking, image recognition, payment processing) from other providers to existing solutions or build new applications using services by third-party providers. In all these cases, specialists don’t have to deal with source code, trying to understand how the other solution works. They simply connect their software to another one. In other words, APIs serve as an abstraction layer between two systems, hiding the complexity and working details of the latter.


Digital products with a good user interface give you a competitive edge in a constantly growing world where companies are starting to realize the importance of good user experience. As a result, they are creating solutions that are functional and elegant while enhancing people’s everyday lives.

When we think of what makes a good interface, we may often think of how it looks or as designers call it, the UI or the visuals. Visuals make apps approachable as they bridge functionality and aesthetics. This ensures better user engagement and overall enjoyment because it makes inherently hard to understand concepts/tasks accessible and “easy”.

The user interface of apps are important because that is how people interact with your product to achieve their needs and goals.

It’s not all about the UI. Functionality and good visuals are important in establishing your brand and relationship with customers. The chances of someone using an app with good visual design is higher despite its functionality. When you have functionality and good visuals, it increases customer loyalty in that your customers will trust you in helping them in comparison to other places.

If your organization specializes in digital products, you need to work together with product teams to make your product stand out and this is by defining a specific problem, specific users and making your product approachable and easy to use for them.

For any product, physical or digital, it needs to be:

Valuable- It doesn’t matter if an app is functional and beautiful, it first and foremost needs to be addressing an user need or else it’s useless. This is why finding market fit and talking to people to validate whether or not your idea works while also defining your user base in the process is a crucial step to having a profitable product. It’s not just about the idea, but about whether or not you can have a sustainable business with it.If people want to use your product, it comes from understanding their problems and solving them. Don’t think about the details and intricacies first until you determine specific problem and user base.

Accessible– If you want your app to reach lots of people, you can’t be thinking about edge cases. In UX design, the goal is to not have edge cases but to consider as many types of users who would benefit from using your product. You should clearly define all of your intended users and start with people who have the most defined and specific needs. Once your intended users are satisfied, scale up and design for different kinds of users. This allows you to properly scale your product while considering the different needs of your potential users and addressing issues early on.

Intentional- As a designer, we need to make decisions. Our designs should be grounded on a solid rationale behind what the problem is, and who our users are. How will our decisions influence their experience, solve their pains and acheive their goals? Is this something that will help them get to point A to point B as painlessly as possible? What will they think/do at this step of the experience? Designers need to be able to answer these kinds of questions clearly and confidently.

Intuitive– When people interact with apps, they shouldn’t think about what they are doing, but to just do what they need to do in achieving their goals. Designers need to think about how the user will interact with the app and minimize the amount of time it takes for them to complete tasks. This ensures users will finish what they need to do without abandoning the app or questioning how to do something.

Invisible- Following intuition, good design is when users don’t even need to think about what they are using, let alone how it is designed. They just use it and it feels instinctual.

Beautiful- If you have an app that is based on a core need and is functional, you are 50% there. If you want to have a competitve edge over other products and have your customers invested in your brand, the app needs to be elegantly designed. Beautiful designs can be a double edged sword. They can make inherently hard experiences effortless by guiding the user or highlighting important information or they can complicate experiences by not offering affordances or don’t meet accessibility guidelines due to looking too flashy.

Examining Engagement

Along with good interfaces, companies are starting to take ownership of the saying “the customer is always right” and a new product that is leveraging customer service is called Fooji. Fooji is an advertising platform that connects fans to brands they love by incorporating digital and physical experiences to heighten customer and business interactions. Customers benefit through engaging with big brands whether it be through social and chat networks. Big brands understand their customers through fun fan interaction and provide them with physical products delivered directly to their doors.

I download the app on my Iphone 5S (I’m old school I know), and am met with a screen of an emoji (Fooji’s logo) with different log in options. I am not entirely sure what the app entails from here, but the emoji logo, friendly font and bright colors express something fun and trendy, drawing me in.

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Author: refuge_2020

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