Generally, a repipe consists of new water lines, hose connections, supply lines, and valves, as well as a new water main shut-off inside the home. All of these will be replaced with more efficient, higher-quality materials.

"New plumbing" could simply just mean new plumbing fixtures and not necessarily a new copper or pex re-pipe of the home. Plumbing supply lines - old are typically galvanized which have the potential to leak or burst. New re-pipes are done in copper or pex.