Reserved Space is virtual memory that has been reserved for future use by a process, but has not been mapped or committed. ...

Reserved Space is virtual memory that has been reserved for future use by a process, but has not been mapped or committed.  Write Copy protection is used when memory is shared for reading but not for writing.  When processes are reading this memory, they can share the same memory, however, when a sharing process wants to have read/write access to this shared memory, a copy of that memory is made.