A bridgehead (also 'Bridge-head'; French "tête-de-pont") is a military
fortificationthat protects the end of a bridgethat is closest to the enemy. The term has been generalized in news coverage and the vernacular to also mean any kind of defended area that is extended into hostile territory (also called a foothold or incorrectly, a beachhead), in particular the area on the farside of "a 'defended river bank' or a segment of a lake or riverine coastline", such as the Bridge at Remagen, and is especially applied when such a territory is initially seized by an amphibious assaultwith the tactical intent of establishing a supply line across the geographic barrier feature to allow further operational manoeuvre.
As the process of moving an army over bridges is slow and complicated, it is usually necessary to secure it from hostile interruption, and the works constituting the bridge-head must therefore be sufficiently far advanced to keep the enemy's artillery out of range of the bridges. In addition, room is required for the troops to form up on the farther bank. In former days, with short-range weapons, a bridge-head was often little more than a screen for the bridge itself, but modern conditions have rendered necessary far greater extension of bridge defences.
Bridgeheads typically exist for only a few days, the invading forces either being thrown back or expanding the bridgehead to create a secure defensive
lodgementarea before breaking out into open country as happened when the U.S. 9th Armored Divisionseized the Ludendorff Bridgeat Remagenin 1945 during World War II. In some cases, such as during the Gallipoli Campaignin World War I, a bridgehead may exist for months.
The term has also come to be used in a figurative sense, for instance in
business, where a marketing"bridgehead" might be a specialized use of a new product in a particular market segment, in preparation for selling it against entrenched competitors across an entire market.
Uses in Information Technology
In IT, generally speaking, a bridgehead is a server that represents one network in another network.
For example, in directory services, a bridgehead server is a domain controller that replicates directory information into a local site from a remote site [ [http://support.microsoft.com/kb/271997 Microsoft Support - Description of Bridgehead Servers in Windows 2000] ] [ [http://www.ucertify.com/article/What-is-bridgehead-server.html uCertify - What is a Bridgehead Server?] ] .
Wikimedia Foundation. 2010.