Fairfax County, officially the County of Fairfax, is a county in the Commonwealth of Virginia. It is part of Northern Virginia and borders both the city of Alexandria and Arlington County and forms part of the suburban ring of Washington, D.C. The county is predominantly suburban in character with some urban and rural pockets.

As of the 2020 census, the population was 1,150,309, making it Virginia's most populous jurisdiction, with around 13% of the Commonwealth's population. The county is also the most populous jurisdiction in the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area, with around 20% of the MSA population, as well as the larger Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Statistical Area, with around 13% of the CSA population. The county seat is Fairfax, although because it is an independent city under Virginia law, the city of Fairfax is not part of Fairfax County.

Fairfax was the first U.S. county to reach a six-figure median household income and has the third-highest median household income of any county-level local jurisdiction in the U.S. Fairfax County, as part of the Washington, D.C. metropolitan area, is usually included atop or near the top of lists of the wealthiest areas in the United States.

The county is home to the headquarters of several intelligence agencies such as the Central Intelligence Agency, National Geospatial-Intelligence Agency, National Reconnaissance Office, National Counterterrorism Center, and Office of the Director of National Intelligence as well as the headquarters of several aerospace manufacturing and defense industry giants. The county is also home to the flagship campus of George Mason University, and headquarters to seven Fortune 500 companies, including three in the Falls Church area, though not in the independent municipality of Falls Church.
Give an introduction of Fairfax county in Virginia.
Fairfax county locates in northern Virginia, it is bounded on the north and southeast by the Potomac River.  The county has a populate of 1,164,025 in 2022, with a growth of 13,716 from 2020.  It is also the most populous jurisdiction in the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area

Fairfax has a thriving economy, attractive to business and is headquarters to several Fortune 500 companies.  Fairfax has excellent schools, it's public school system is top-ranked in the nation, and is home to George Mason University.  

Fairfax County is also home to many historic sites and cultural attractions; like Mount Vernon, Wolf Trap national park.