from
The Free On-line Dictionary of Computing (8 July 2008)
copying garbage collection
A {garbage collection} method where memory is divided into two
equal halves, known as the "from space" and "to space".
Garbage collection copies active cells from the from space to
the to space and leaves behind an invisible pointer (an
"indirection") from the old position to the new copy. Once
all active cells have been copied in one direction, the spaces
are swapped and the process repeated in the opposite
direction.