I think the basic difference between library and framework is that if you use framework it's responsible for bootstrap of your application, and library does not.<p>But also framework drives structure of result codebase - filenames convention, directory structure, maybe way you implement your features.
To me framework is a set of libraries, glued together with some infrastructure code. Framework provides some conventions that speed up most common tasks.<p>It may be possible to use framework as a library, though there is no or small benefit.