Api means Application Programming Interface
An API defines access to a particular piece of software, without the need for extensive knowledge of the program. If you are working in a photo editing program, and want to print it, the program calls the printer's API to print the file. So it's about not having to know everything to print out something, and what it all needs. You only need a call to an API, and you can still print. The term API has become known to the general public when websites also went on to provide APIs, and important part of Web 2.0. Using the Google Maps and Flickr API, it is possible to quickly and easily visualize the location of the photos.
What is an API? YouTube UcHhwsTIK_o [/youtube]