PLAN – Is an executable DB2 object. A DBRM we can bind directly to a PLAN or a PACKAGE we can bind it to a plan. In the BIND cards, we need to give PLAN name and PACKAGE name. A COLLECTION, it is again DB2 object. We keep all the packages in a plan.
We can see PLAN details in SYSPLAN catalog table.
PACKAGE – It is basically a DB2 object. All the similar DBRMs, we can keep in a PACKAGE. It is itself is not executable.
We can see PACKAGE details in SYSPACKAGE catalog table.
COLLECTION – It is again DB2 object, during BIND, we need to give PACKAGE and COLLECTION id details.
We can see all the details in SYSCOLLECTIONS catalog table.
DBRM – This is load of DB2 code. This will be generated during pre-compilation. There will be one DBRM for each program.
VERSIONS – It is a concept for PACKAGE versions. We keep different versions of a packages. Since, each update in PACKAGE will put different version and keep old version of PACKAGE. In the production it is useful keeping old version.