API

Short for application programming interface, an API is a specified set of rules and requirements that software programs can utilize in order to establish communication with each other. Strictly speaking, APIs function to interface between various software programs in order to facilitate interaction. APIs can be created for applications, libraries, databases, and operating systems as a way of specifying their content and operating protocols to other interloping programs. Specifications can include data structures, protocols, and routines that dictate how communication will occur between various programs. APIS can range from the very general (full API) to extremely specific (APIs created to execute an explicit function). Popular APIs include Google Maps, Facebook, and Twitter, to name a few.