The San Francisco Bay Area, popularly known as the 'Bay Area' to local residents, is a diverse and thriving metropolitan region that encompasses San Francisco Bay in the northern part of California. San Francisco, North Bay, East Bay, South Bay, Peninsula and Santa Cruz make up the Bay Area regions. They are divided into nine counties: San Francisco, San Benito, San Mateo, Santa Clara, Santa Cruz, Alameda, Napa, Solano and Sonoma.

Although San Francisco City is identified as the cultural and traditional center of the Bay Area, it is not the largest or most populated city within the area. Historically, the Bay Area traces its roots from Spanish explorers who first set foot in the region and founded a Catholic church in 1776.

Bay Area is distributed over a population of nearly seven million residents (as of the latest count in 2006). People are scattered over a number of suburban and urban centers, hence, the general area name. Its generic name is derived from the various regional natures of the area, with no specific reference to a city.

Studies place the population of San Francisco Bay Area among the best in the country for overall education placement, competing with Washington D.C. and Boston. East Bay is known for being the home of famous seminaries and universities, namely Berkeley or the University of California and Stanford University.

Weather is generally agreeable but unpredictable, as bodies of water fence in the land area. Spring casts mild and cloudless days, summer is cool and overcast, and fall weather is warm, hot and sunny, with mild and clear nights, while winter brings in the most humid rainy days, alternating with clear and sunny skies.

The diverse geography is broken up into prime residential and industrial spaces, covering villages, towns and cities, parks in the national, state and regional levels, as well as airports and military bases. All these are connected by a modern and efficient transport system composed mostly of trains (commuter rail and railroads), highways and roads.

Considered as one of the most affluent regions in America, the San Francisco Bay Area boasts having the most median income per household, across the nation. Six out of the 10 best Californian areas that have the most income per capita (Belvedere, Diablo, Atherton, Woodside and Portal Valley) are all in the Bay Area. The popular Alameda, Contra Costa, Marin, San Francisco, San Mateo and Santa Clara counties in Bay Area are also part of the top 100 income per capita counties in the States. As a result, the Bay Area real estate appreciated to the level of the 'most expensive zip code' league. In 2005, Forbes Magazine listed Atherton, Diablo, Ross, Nicasio, Los Altos, Tiburon, Los Gatos, Portal Valley and San Francisco as one of the top 50 most expensive places to live in.