A complex robotic task may often be represented as a sequence of simpler tasks.  The number of these simple tasks or "primitives" may be quite small yet still provide a great deal of functionality.  This is true in a computer game rendering engine where the basic task is to manage collections of triangles.  It is also true in the English language where we build up letters into words and the words are then put together into sentences, paragraphs, chapters, and finally books.  In all cases, the actual basic elements are rather few.

Primitives are the building blocks of behaviors when programming a Garcia robot.  Some examples of Garcia primitives are moving straight ahead a specified distance or turning a specified angle.  To execute a primitive, Garcia runs a small program stored in its own memory.  Garcia can store over a dozen primitives.  They are stored in EEPROM so they can be updated or changed when necessary.  These primitives interact with the monitor to make sure that the robot acts appropriately when encountering special conditions.  For example, when the robot is moving forward it must stop when the downward-looking rangers mounted near the front of the robot detect a ledge.

The Garcia API provides routines for creating behaviors, assigning behavior parameters, scheduling behaviors, and checking the results of each robot action.