Migration is the process of moving data from one environment to another. Migration, hopefully, prevents the inaccessibility of data due to damaged or obsolete environments and can provide improvements in efficiency, functionality and stability. Refreshing and migration are not without their potential dangers. Refreshing may occur too late and the damage to files may have already occurred. Continually moving files from one medium to a different medium may cause a loss in the bits that make up a file.
Migration is time consuming and presents risks of bit fade or loss.
The difficulties of predicting the timing and direction of technological change present challenges to planning for both strategies. Researchers are investigating the use of emulating older software and file formats and the preservation of legacy technologies to allow the reading of earlier files without the risk of refreshing and migration. Both of these strategies are still in the future and fraught with their own risks. Digital archeology is a new endeavor that works toward recovering data from obsolete or damaged files. Digital preservation is challenging due not only to technology issues.