A breakout board in cryptocurrency mining is a crucial component used to distribute power from high-wattage power supplies to multiple ASIC miners or GPUs. It helps to split the electrical power to ensure all mining hardware gets the necessary current, reducing the complexity and increasing the efficiency of power management in a mining rig. Breakout boards are typically used in large-scale mining setups where multiple high-power devices operate simultaneously, and they can help prevent overloading circuits while optimizing the distribution of electrical power.