Cluster, Cloud, & Grid

Choking on the following concepts and need confirmation or clarification: a cluster is an architectural pattern of server nodes being grouped together, and two competing instances of the cluster pattern are cloud and grid solutions.

Either way, what are the pros/cons of using clusters, clouds and grids (in relation to each other), and what criter开发者_C百科ia does one use to figure out which solution is best?

Thanks for any help!

Cloud and grid are just marketing term for the same thing and both are just clusters owned by somebody else.

You can only answer the question if you pick a definition of each - and that will answer your question!