What's the difference between magnetic and electromagnetic resistance?

Standard magnetic resistance uses a manual knob or lever to move a magnet closer to or farther from the flywheel, giving you fixed resistance levels (typically 8 or 16). Electromagnetic resistance — used on the Hydrow Wave and MERACH's R7-tier machines — adjusts the magnetic field electronically, allowing app-controlled or workout-driven resistance changes. The tradeoff is price and the need for power.