Exactly. The way I see it, you can think of a piece of code sort of like chain links. GPL code looks like this: http://ace.imageg.net/graphics/product_images/pACE2-988564dt... AND it requires that ever piece 'below' it on the chain also look like that. Open source, BSD-licensed code also looks like that, but allows later links to be closed as well.
The upside to GPL is that any link N has the same rights to use and modify N-1 as 2 had on 1, with the downside being that N has limited rights on itself. BSD grants maximum control to each link, with the downside being that any given link may choose not to allow any links to be added below it.
The upside to GPL is that any link N has the same rights to use and modify N-1 as 2 had on 1, with the downside being that N has limited rights on itself. BSD grants maximum control to each link, with the downside being that any given link may choose not to allow any links to be added below it.