What is "Grid Computing"

I've seen this mentioned several times now. What is it?

Sun uses this term a lot.
Originally known as compute farms. An environment that is the ultimate realisation of resources like Web Services.
If you think how electricity is supplied over grids, I think you'd get the idea. I've taken the term on-demand computing to mean the same thing.
Perhaps wrongly.
regards
[ September 09, 2003: Message edited by: HS Thomas ]

Is it kinda like the whole seti-at-home thing? but perhaps a bit more generic?

seti@home is the network of home PCs shared for looking for ExtraTerrestial life, that one?
I expect so. But Sun might disagree. They are really into the management of grid computing and treat the grid as a network-based Web Service rather than a collection of individual nodes.
regards