There are several types of refrigeration systems, including vapor-compression, absorption, and evaporative cooling systems. Vapor-compression systems use a compressor to compress refrigerant, which then condenses, expands, and evaporates to transfer heat. Absorption systems use a heat source to drive the refrigeration cycle, whereas evaporative cooling systems use the evaporation of water to cool the air. Each type of system has its own advantages and disadvantages, and the choice of system depends on the specific application, climate, and energy requirements.