Grid Computing has been chosen as the computing paradigm for providing the resources
necessary to handle the data produced by the LHC experiments. With more than 15 Pbytes 
being added each year and the need of continuous use of more than 250.000 CPU cores 
a substantial problem had to be solved. The lecture will describe the underlying 
technology and the infrastructure that has been build. An outlook will be given 
on it's most likely evolution.