Definitions
1.verb(followed by on or upon) To concentrate one's attention."I have to focus on my work."
2.verbTo cause (rays of light, etc) to converge at a single point.
3.verbTo adjust (a lens, an optical instrument) in order to position an image with respect to the focal plane."You'll need to focus the microscope carefully in order to capture the full detail of this surface."
4.verbTo concentrate one’s attention."If you're going to beat your competitors, you need to focus."
5.verbTo transfer the input focus to (a visual element), so that it receives subsequent input."The text box won't receive the user's keystrokes unless you explicitly focus it."
6.adjectiveDirecting all one's efforts towards achieving a particular goal.
7.adjectiveDealing with some narrowly defined aspects of a broader phenomenon.