An oak is a tree or shrub in the genus Quercus (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 600 extant species of oaks. The common name "oak" may also appear in the names of species in related genera, notably Lithocarpus. The genus is native to the Northern Hemisphere, and includes deciduous and evergreen species extending from cool temperate to tropical latitudes in the Americas, Asia, Europe, and North Africa. North America contains the largest number of oak species, with approximately 90 occurring in the United States. Mexico has 160 species, of which 109 are endemic. The second greatest center of oak diversity is China, which contains approximately 100 species.

Oakland International Airport is five miles south of downtown Oakland, in Alameda County, California. It is owned by the Port of Oakland. It is one of three international airports in the San Francisco Bay Area. The airport has passenger service to cities in the United States, Mexico and Europe. Cargo flights fly to cities in the United States, Canada and Japan. OAK is the closest airport to the San Francisco financial district—both geographically and by public transit.