The last decade, the term 'Grid' has been a key topic in the field of high performance/distributed computing. The Grid has emerged as a new field of distributed computing, focusing on secure sharing of computational and storage resources among dynamic sets of people and organizations who own these resources. This sharing of resources can give people not only computational capabilities and data storage capabilities that cannot be provided by a single supercomputing center, but it also allows them to share data in a transparent way.
One of the reasons that Grids are popular lies with the change in mode of collaborating and problem solving in a number of sciences. Research in various sciences is now an international and multi-institutional matter. High Energy Physics, Earth Observation and Bioinformatics can serve as an example in this respect. One very successful example with respect to Grid computing is the WLCG collaboration where about 150 sites putting together about 250000 CPU cores, 160 Petabyte (160 million gigabytes) of disk storage and 90 Petabyte of tape storage to process data from the Large Hadron Collider (LHC) for the benefit of thousands of scientists around the globe. WLCG makes use of the EGI and OSG Grid infrastructures and Grid infrastructures from Asia.