Focus — Ayn Rand Lexicon:
"“Focus” designates a quality of one’s mental state, a quality of active alertness. “Focus” means the state of a goal-directed mind committed to attaining full awareness of reality. It’s the state of a mind committed to seeing, to grasping, to understanding, to knowing.
“Full awareness” does not mean omniscience. It means: commitment to grasp all the facts relevant to one’s concern and activity at any given time . . . as against a splintered grasp, a grasp of some facts while others which you know to be relevant are left in fog. By “full” I include also the commitment to grasp the relevant facts clearly, with the fullest clarity and precision one is capable of.
“Focus” is not synonymous with “thinking,” in the sense of step-by-step problem-solving or the drawing of new conclusions. You may be walking down the street, merely contemplating the sights, but you can do it in focus or out of focus. “In focus” would mean you have some purpose directing your mental activity—in this case, a simple one: to observe the sights. But this is still a purpose, and it implies that you know what you are doing mentally, that you have set yourself a goal and are carrying it out, that you have assumed the responsibility of taking control of your consciousness and directing it . . . ."
Leonard Peikoff, “The Philosophy of Objectivism”