The world-wide-web changed the way we share and distribute information but did very little to make computing power or data storage more assessable. The aim of the Grid was to build on existing Internet protocols and to develop `middleware` which would allow simple and transparent use of resources wherever they may be world wide. Since the start of the GridPP project in 2001 the UK has been at the forefront of developing these technologies and providing resources to process the data generated by the LHC. The grid performed very well enabling results to be processed and results to be published faster than ever before. This directly contributed to the confirmation of the Brout-Englert-Higgs mechanism.
There were many challenges to developing a Grid that would deliver the kind of robust, high-performance system required. The LHC experiments record 15 million gigabytes (15 Petabytes) a year. Searching for the Higgs boson which is expected to only occur a few times per million events requires complex analysis of the data in order to both model what is expected and verify that experimental data is consistant with expectations. Tens of thousands of computing cores are required to process this data. In 2014 the WLCG totalled about 388,000 logical CPU cores spread world wide with the UK (GridPP) contribution being approximately 50,000.
To cope with this scale of computing and data, experiments have put globally distributed resources at the physicists fingertips. Particle physicists were therefore heavily involved in providing requirements for the Grid, in developing higher levels of the middleware, and in providing a real-world use case for the early deployment of software. They are now working successfully with researchers in computer science and many other fields, to optimise the computing models over time to provide the most efficient use of the WLCG resources. The WLCG has been part of wider European grid projects such as EGEE and EGI which supports Virtual Organisations (VO's) from many disciplines outside of Particle Physics.
The GridPP website contains more information.
The Oxford E-Research Centre web site has details of various e-science projects that Oxford University os also involved with.
For the background to the fundemental design ideas of Grid Computing see The Anatomy of the Grid: Enabling Scalable Virtual Organizations