All of us in the IT industry have a peculiar behavior.
A buzzword spontaneously appears, we all echo it fervently, but we're not really 100% sure what it all means.
At some point, we remember that customers buy solutions to business problems, and don't spend a lot of money on buzzwords, so we get down to brass tacks and figure out what this stuff might really mean, and what business problem it might solve.
Grid is a reasonable case in point. Just getting to a common definition is difficult. And trying to figure out "OK, exactly what problem does this solve?" gets even more interesting.
So let me try and wade in.