The S3 is the battalion's operations and training officer. A member of the battalion's command staff, an S3 typically holds the rank of major or lieutenant colonel in the Army. The S3 is also the battalion training officer, ensuring the ongoing military education of the battalion's personnel.
The Apicomplexa (also called Apicomplexia) are a large phylum of parasitic protists. Most of them possess a unique form of organelle that comprises a type of plastid called an apicoplast, and an apical complex structure.
Application program interface (API) is a set of routines, protocols, and tools for building software applications. An API specifies how software components should interact and APIs are used when programming graphical user interface (GUI) components. A good API makes it easier to develop a program by providing all the building blocks.