block library
An installed directory that provides blocks for constructing models. A library contains files such as those that define blocks, library-keys and installation scripts. In general, a library contains one or more palettes which are special .scm files that expose blocks through the Palette Browser once the library is installed. The hierarchical structure of a palette does not necessarily reflect the organization of the block files in a library. The standard System block library of the software contains two palettes: Base and Advanced.