SAP memory (Global Memory): - is available to a user during

the entire duration of a terminal session. Its contents are

retained across transaction boundaries as well as external

and internal sessions.

ABAP/4 memory

The contents of the ABAP/4 memory are retained only during

the lifetime of an external session (see also Organization

of Modularization Units). You can retain or pass data

across internal sessions. The EXPORT TO MEMORY and IMPORT

FROM MEMORY statements allow you to write data to, or read

data from, the ABAP memory.