API stands for Application Programming Interface. Like any other interface, an API is simply a common point of interaction that allows two different systems to collaborate with each other. In this case, the two interfacing systems are computer applications, and the mediator is the application developer, or programmer.

APIs allow applications to dependably retrieve information from other software on the web.

FedEx APIs are the gateway between your current business application and FedEx logistic solutions.

Imagine two applications with differing functionalities. While one may be focused on receiving orders from customers, the other may only concern itself with the real-time location of packages. The consumption of one application's resources would likely be very beneficial to the other. Would it not make sense for the application that receives orders to also show the current shipping status of the order, within a single view? But how do we go about accessing this information across application boundaries? This is where APIs come in. When two applications agree upon an API, one can consistently expose valuable information for presentation within the other.