1) The library cache contains the shared SQL area, PL/SQL code, and some control structures.
2) The shared SQL area contains parse trees, and execution plans for SQL statements.
3) The library cache holds PL/SQL packages, procedures, and functions. Multiple users of a PL/SQL program unit all share a single copy of the code
4) Control structures in the library cache include locks and library cache handles
5) To improve performance, the data dictionary cache holds the most recently accessed data dictionary records
6) Control structures in the main area of the shared pool include character set conversion memory and network security attributes