The "Bay Area" refers to the nine counties (Sonoma County, Napa County, Marin County, Solono County, Contra Costa County, Alameda County, San Mateo County, San Francisco City & County, and Santa Clara County) which make up the greater metropolitan San Francisco Bay Area. (All nine counties touch the San Francisco Bay, and some would also include Santa Cruz County.) The three major cities are San Francisco on the peninsula, Oakland in the East Bay, and San Jose in the South Bay. This "tri city" metro area is ranked fifth in the nation by population, behind New York/New Jersey, Los Angeles, Chicago, and Washington, D.C. (In that order.) With seven million inhabitants (possibly less after the tech bubble burst), it contains 20% of the population of California, the most populated state. (Other metro areas are Los Angeles with 47%, San Diego with 8%, Sacramento with 5%, and Fresno with 3%.) (U.S.)
While a slightly different flavor, it is still California with innumerable numbers of cars, freeways, suburbs, and strip malls. Smog certainly exists, and tends to linger as a brown film over the Bay, getting worse in the summer months, but is not nearly as bad as Los Angeles.
Notable differences from Los Angeles include the Bay Area Rapid Transit System (BART) which links up the East Bay with San Francisco using a state of the art (although extremely expensive) high speed rail system. On the darker side of transportation, seven toll bridges criss cross the bay, connecting major cities. (Most notably the Golden Gate Bridge, the worlds largest (not longest) suspension bridge, and the San Francisco-Oakland Bay Bridge.)
The Bay Area also contains the City of San Francisco, the densest urban area west of the Mississippi (ranked fifth in the nation), shrouded by fog, and covered with a seemingly illogical maze of streets designed to thwart tourists who enjoy making left hand turns. Declared by many to be the "Most Beautiful City in the World" (people who have obviously only seen pictures), it is one of the last strongholds of liberalism in the United States. Do not be confused, though, because San Francisco is no more a part of the Bay Area than it is part of the United States. This is why most presidential candidates will visit places like San Jose and Palo Alto, avoiding "those damn liberals" who like to have protests and picket lines. (San Francisco is also physically separated as it is surrounded by the Bay to the north and east, the Pacific Ocean to the west, and San Bruno Mountain to the south.)
Oakland is the traditional Bay Area suburb dating back to the nineteenth century. It is home to Huey P. Newton and Bobby Seale, founders of the Black Panther Party for Self Defense, as well as the Cypress Street Viaduct, a double decker freeway built on bay fill over Cypress Street that quite dramatically collapsed during the 1989 Loma Prieta Earthquake, killing about fifty.
Oakland's neighbor to the north, Berkeley, is notable, if not for its size in land or population, by its tremendous ego. Home to the prestigious mother campus of the University of California, it was center stage it much of the free speech movement and Vietnam war protests during the latter half of the nineteen sixties. (Despite popular belief, this was a different movement than the counterculture hippies living in San Francisco.) The city of Berkeley, like San Francisco, is incredibly liberal, and to be honest quite insane. (My favorite scheme was providing flags at intersections that pedestrians could wave at oncoming cars and then return to the basket on the other side of the street. The flags were gone the last time I visited, but apparantly have now been replaced.)
Santa Clara County, before the 1960's, was a collection of farms that grew mostly fruit in the mild climate and fertile soil of the Santa Clara Valley. After Lockheed moved its facilities from Southern California to Sunnyvale, a boom of technology ensued creating the semiconductor and computer industries that exist today. Now, there are a handful of orchards left, and 1.7 million occupants. This area is generally considered Silicon Valley (although it would seem a more appropriate name for a desert.) It has the highest Internet and computer usage and more EPA superfund sites than any other place in the United States. Other than the technology industry, the Valley lacks very many definable characteristics.
The entire Bay Area is a very beautiful place at all times of the year. Winter rain only seems to make the grass greener, the fog only adds more contrast, and the summer smog only tinges the horizon rather than blotting it out completely. It is also full of very unique oddities, mostly concentrated in San Francisco, making the City a sickeningly appealing tourist destination.
As to the supposed rivalry between the Bay Area and Los Angeles, I don't quite know what to make of it. Many people in the Bay Area are bitter because the flow of energy and water goes south, although this seems like a slightly silly reason to me. A better reason for annoyance would be the domination of Los Angeles in state politics, which until recently was very conservative. (In fact, only in the 1990's did Los Angeles County become majority Democratic and help elect Bill Clinton as well as Grey Davis, for whatever they were worth.) In my experience, both areas have a love hate relationship with their populations, as any highly populated region of the world. Many people love the Bay Area because it is beautiful, but hate it because it is expensive and fairly sedate. Similarly, many love Los Angeles because of its size and prestige, but dislike the car culture and the dependence on freeways and smog that comes with it. In the end, both are California, and both are often at odds with the rest of the country.
U.S. Census Bureau. Census 2000 Rankings and Comparisons Population and Housing Tables. Washington: U.S. Gov,2 Apr. 2001. 17 Jul. 2003 .