API – Programming interface of a software
An API (short for “application programming interface”) is a programming interface that is used for communication between different elements of a software system. An API contains source code, which for example the hardware of a computer needs, in order to successfully run from the software system. The API thus enables access to hardware and databases, but also helps to convert various information more easily into a graphical user interface.
Four types of API
There are four different types of programming interfaces. A function-oriented API communicates via handles, which serves as a response to the call of a function. A typical representative of this type is the BIOS of a computer. File-oriented programming interface causes files to be opened, read, written to, or closed. These interfaces are particularly important in UNIX systems for addressing device drivers. Object-oriented programming interfaces are more flexible systems that usually work on the basis of a type library. A protocol-oriented API is not dependent on the operating system or the hardware. A distinction is made here between protocols that are generally valid and protocols that relate to specific applications.
API in e-commerce
In Internet commerce, the API plays a very important role in the exchange of information between an online store and various service providers. According to the German Digital Industry Association, in 2011 more than half of online retailers already offered Internet payment services such as Paypal, moneybookers or Sofort as payment methods. In order to be able to process a payment via such service providers, an API is required to transfer the necessary data, for example the amount to be paid, the account data or the e-mail addresses of the parties involved, or the purpose of use. Anyone who wants to set up a connection between their online store and an enterprise resource planning system or billing software must also make use of the API in order to be able to transfer the relevant data. In addition, there are printing services that can be used, for example, to automatically print out shipping documents, transport bills or invoices. Here, too, the information is transferred via API.
API in marketing
The transfer of e-commerce data to external service providers also plays a role when an online store uses it to market its products. If the products are to be listed on price comparison sites and price search engines, a corresponding API is set up in the online store to which the respective comparison site can connect. For this purpose, files are usually stored on the online store’s web server that contain the required data in tabular form – from product names and images to price and shipping costs. In addition, an automatic transfer of products to partner stores can also be programmed via an API. For example, new products in the online store can be automatically transferred to a partner store on Amazon or a dealer store on Ebay.
