A behavior is a definable unit of activity initiated by certain inputs and which generates certain outputs as a result of its activity. In most behavior-based work, these units are very low-level in nature and are connected directly to sensors and effectors.
We extend this concept of a behavior in two directions to make it more generic in nature. First, the concept must embrace higher-level behaviors, since human users will need more from the vehicle than simple non-colliding motion through the environment, nor will they want to specify every detail of the vehicle's actions during a mission. A vehicle will need to do some planning or planning-like behavior to map the high-level descriptions given by a user to actual actions to take in the world. Second, the concept must be expanded to include non-motion behaviors, for example, communication and homeostatic functions. The two extensions to the behavior concept overlap, since the higher-level behaviors naturally begin to incorporate non-motion concepts, including planning. This extended notion of behaviors is given the name generic behavior.
Another connotation of generic is operative here, the sense of the generic behaviors being applicable across a spectrum of different vehicle types. Some behaviors are obviously easily transportable, such as low-level movement and (to some extent) obstacle avoidance, while others that depend on the particular vehicle configuration would not be. The higher-level, non-motive GBs are also good candidates for generality, since they will not usually depend on the vehicle configuration and most useful vehicles will need their functions.