Grid Computing Presentation

What is grid computing? No challenges.It its technology is very urgent. Frndz Plz help me out.
Frndz hi im pursuing M. Sc (Computer science) I want to know about grid computing technology and its challenges. I have to give seminar on this subject and im not aware about it. I must make the presentation tomorrow. Can u all help me. Please guys help me out there. Thank you in advance … Neetu.
Grid computing in Laymans term a cluster of computers working together for a given task, but these clusters of computers may or may not have the same version of operating system, applications, hardware, etc. and are in geographically divided field. Its merits are high performance, availability, render farm, distributed computing. If u find these terms to be difficult, u can google these terms and it will be clear to you.
Presentation by National Autonomous University of Mexico