Question:

What is a grid?

Answer:

A relatively new idea, a grid breaks the classical situation of one server hosting many sites, and instead connections hundreds of servers together.

In classical virtual hosting, one server may host 100 websites. If one account suddenly tries to use too many resources, the server may crash, making all 100 websites inaccessible. A grid solves that problem by using 100 servers to host 10000 websites. By distributing all sites across so many servers, it becomes very unlikely for one site to crash the entire grid.