The eBay API is the heart of the an Application programming interface

Application programming interface

An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...

 for interacting directly with the eBay database. The communication occurs over the Internet

Internet

The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

 with in the XML

Extensible Markup Language

Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....

 format. Using the API, the application can provide a custom interface, functionality and specialized operations that is not otherwise afforded by the eBay interface.

Functionalities

With the eBay API, developers can create programs that can

• Display eBay listings
• Get high-bidder information for sold items
• Get the current list of eBay categories
• Leave feedback about other users when finishing a commerce transaction
• Retrieve lists of items a particular user is currently selling
• Retrieve lists of items a particular user has bid
• Submit items for listing on eBay
• View information about items listed on eBay

As the API does not dependent on the eBay User Interface, it makes it possible to create stable, custom functionality and interfaces that meet business needs.