This is an Example of a Fixed End bridge.  Simply, there is a solid foundation on both ends to distribute the load to the ground.  Click the Red Box to get a close up of what a typical fixed end connection looks like. 
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ONE HINGED

This is an example of a single hinged bridge.  There is a hinge at one end of the bridge and the other has a fixed end.  Click on a Red Box to see what a typical connection looks like in this type of bridge.
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TWO HINGED 

 
This is an example of a Two Hinged bridge.  There is a hinge at each end of the bridge to support it and transfer the load to the ground.  
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THREE HINGED

This is an example of a Three-Hinged structure.  There are hinges at each end and a third hinge in the middle.  The load is distributed to the ground via the hinges.
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OPEN

This is an example of how an open arch works.  As you can see the load is transferred down through its supports.
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