abstraction: See generalization.
action: One of a set of occurrences that processes data, either sequentially or concurrently. See also event.
activatable subworkspace: A subworkspace that you can activate and deactivate programmatically to enable and disable entire portions of your application.
application programmer's interface (API): A set of public attributes, methods, and procedures that provide programmatic access to the private capabilities of a module or set of modules. You typically create APIs for reusable modules in large-scale applications and domain-specific toolkits. See also private layer and public layer.
array: A data structure that defines a fixed-length series of items or values. See also list.
asynchronicity: The time-dependent behavior of a module. Contrast with concurrency.
atomicity: Procedural processing that maintains a single processing thread, without any wait states. See also single-threaded processing.
attribute: A common characteristic of a class. In object-oriented terms, an object's attributes are its data. The public attributes of a class are part of its protocol. See also method.
attribute access facility: A feature whereby you can directly access every system-defined attribute of every built-in G2 class, using sequences and structures.