Focus has several meanings:
- In optics, focus means that an image is correctly rendered on a plane. This involves the focal length of specific lenses.
- In psychology, focus as a cognitive process means concentrating selectively on a single aspect of one's environment or thoughts while ignoring other things
- In geology, a focus is a point along a fault where an earthquake begins (hypocenter versus epicenter).
- In Buddhist meditation, focus means concentrating the mind selectively on a single aspect of one's thoughts or images while letting go of all other things until the mind become "single-pointed" ("samadhi") through relaxed focused awareness ("shamatha"). According to Buddhism, focus is related to the "fire element" of the mind and nervous system.
- Wile, Dr. Jay L. Exploring Creation With Physical Science. Apologia Educational Ministries, Inc. 1999, 2000