What is Application Programming Interface

What does API stand for?

Application Programming Interface (API) have existed quite long time ago, since the invention of first computer programs. The first API was developed and released by Salesforce.com in the year 2000, reports developer.ibm.com. In the same year, Ebay released its first web-based API, followed by Amazon starting their new Amazon Web Services (AWS). This gave rise to a new API age, and reached a matured point of hosting external APIs letting the cloud service providers to manage their transaction loads and spike traffic.

API

(API) is a set of commands, protocols and tools used for building software applications. It is a set of code that establishes connection between other two software codes. It can also be defined as a communication bridge between a developer and an operating system to request services while developing an application. In simple words; the software program once developed for some specific purpose can be re-used in developing another application just by referencing APIs which reduces development time, cost and decreasing the probability of errors.

Basic Types of APIs:

Local APIs—offers middleware services to the application programs. For example Microsoft .Net APIs, Telephony API (TAPI), database access APIs, Yahoo Local Search API, Google API and many other freely available APIs developed by large companies for their customer’s internal use.

Web APIs—Web APIs are often called as REST (Representational State Transfer) APIs or RESTful APIs, since there are many requests coming from the users on the internet are mingled. It is mainly used to access the most widely used HTML resources, URLs and web pages through HTTP protocol. Many companies use REST models and simple programming tools for API access and improved business activities through the web.

Remote API—allows accessing and manipulating the remote resources through protocols and different technologies, promoting communication and collaborative working regardless of the OS environment. For example, Java Remote Method invocation API allows invocating the functions that operates remotely and executes in a local environment.

Program APIs—is based on RPC (Remote Procedure Call) technology that makes a remotely running component of a program appear to be local. Example: SOA (Software Oriented Architecture), Microsoft’s WS Series of APIs.

Open APIs—Open APIs are also known as Public API, which lets the owners on a network give universal access to consumers and developers. Open APIs are mostly used by startup companies to publish their newly developed software as an API to encourage the third party developers of different industries to develop it further and innovate as an another new software product.

There is an enormous increase in the use of technology in our day-to-day life, which led to the use of mobile applications in completing our daily tasks. The Internet has become a primary source for APIs and many large companies like Facebook, Google and Yahoo publish their APIs on the internet so that the developers can increase their capabilities. These APIs are embedded with all the new internet features that browse other sites for services and the mobile applications that offer easy access to web resources.

API Technologies:

APIs have revolutionized the way software products are developed by software companies. Over the past decade, the API has evolved based on the advancements in technologies like network, security and software integration that has lead to a matured business. 

REST is the widespread technology used for implementing APIs. Majority of the web APIs available for developers are embodied with REST and it has become prevalent for developing Web APIs. It is because REST offers a lightweight architecture when compared to SOAP and it has an attractive quality of targeting the original audience of APIs.

XML is also a popular choice to implement web APIs due to several factors like it provides a comfort zone for the one familiar with XML and SOAP background.

Current Trends in APIs

API Cloud:

Moving from traditional computing to cloud computing has introduced to new trends like re-using the software components, connecting the same component to different and scaling the number of copies present. These capabilities have brought a shift in the focus of APIs from simple RPC programming models to RPC web-centric models that are needed in the cloud.

APIs as Services:

APIs are also used as tools by many users for a more controlled deployment and development. Services are the current trend in APIs, in future, it may be used a service-based API. SOA and micro-services are the examples of APIs as a service.