merge(To copy the contents of a differencing disk to the parent disk, or to combine the contents of the differencing disk and the parent disk onto a new virtual hard disk. Merging to the parent disk modifies the parent disk and then deletes the differencing disk. Merging to a new disk leaves both the differencing disk and the parent disk intact)
coalesce(To unite or merge into one); merge(To copy the contents of a differencing disk to the parent disk, or to combine the contents of the differencing disk and the parent disk onto a new virtual hard disk. Merging to the parent disk modifies the parent disk and then deletes the differencing disk. Merging to a new disk leaves both the differencing disk and the parent disk intact)