Application Programming Interface (API)

An API is a set of software components that interact with another system, application, library, etc. It allows us to access someone else code. It’s used when two or more separate systems need to work together to achieve something they can’t do alone. This article describes an introduction to API, overview of Application Programming Interface. Summery of the article:

• What is API?
• Examples of API
• Why we should use API? Or Advantages of API

What is API?
Application Programming Interface (API) is an interface which helps us to interchange data from computer, library, and software to another computer, library, and software. It may have many functions/methods. Final API describes only how to use these functions/methods. It is not necessary to know the code those functions/methods.

API is not a user interface. It is a software to software interface. With it applications talk to each other without any user knowledge or intervention. When we purchase something through a web site we provide our credit card information. The web site use API to send the card information’s to remote computer that verifies the information’s. If every thing is OK API send an acknowledgement to web site. Then web site says it’s OK to purchase. As a user we can only see the web site interface. We don’t see some API is working behind the site.

An Application Programming Interface (API) is a set of programming instructions and standards for accessing a Web-based software application or Web tool. Generally Software Company releases its API to the public so that other software developers can design products that are powered by its service. For example we can consider the API of Amazon.com. It released its API so that Web site developers can access Amazon’s product information. Using the API, a third party Web site can post direct links to Amazon products with updated prices and an option to “buy now.”

Examples of API
Today lot of APIs are present and providing us different functionality. Some of them are free, some are commercial. Every day we are using many APIs. Some examples of most popular APIs are given bellow:

• Google map API
• Microsoft UN API
• Java platform API
• Microsoft windows direct X
• ASPI for SCSI device interfacing
• Cocoa and Carbon for the Macintosh
• DirectX for Microsoft Windows
• EHLLAPI
• Java APIs
• ODBC for Microsoft Windows
• OpenAL cross-platform sound API
• OpenCL cross-platform API for general-purpose computing for CPUs & GPUs
• OpenGL cross-platform graphics API
• Server Application Programming Interface (SAPI)
• Simple DirectMedia Layer (SDL)

Why we should use API? Or Advantages of API
We should use API because it has lot of advantages. It reduce our valuable time and cost. For example if we want to show any place in our web site then we can easily do it by using google map API. We need to use google map API and just set Latitude and Longitude of that point. Goggle map API will do everything. We do not need to make map or need not to use satellite or GPS help or some things else.
It provides cross platform facilities.

We can design an API by using different programming language. But remember that, API writing is one of the most difficult tasks in programming. Every thing should be simple, clear and organized.