Ablation devices destroy abnormal tissue via thermal, cold, or electrical energy in minimally invasive procedures. Types include radiofrequency (RF: heat via electrodes, e.g., Medtronic Cool-tip for liver tumors creating 2-6cm zones), cryoablation (freezing with argon/liquid N2, Boston Scientific ICEfx for kidney/prostate with 3-5cm ice balls), microwave (electromagnetic waves, AngioDynamics Solero up to 5cm in liver), pulsed field (PFA: non-thermal electroporation for cardiac arrhythmias), HIFU (focused ultrasound), and laser. Uses: cardiac AFib ablation (90% success), tumor ablation (liver/kidney/lung), varicose veins, pain management.