What type of power supply is most commonly used in computers today?

The most commonly used power supply in computers today is the switching power supply. This type of power supply is preferred because it is highly efficient, lightweight, and capable of regulating different voltage levels effectively. Switching power supplies use a high-frequency switching regulator to convert electrical power, which leads to smaller components and a more compact design compared to linear power supplies.

Moreover, switching power supplies can handle a wide input voltage range and have better energy efficiency due to reduced energy loss during conversion, which makes them more environmentally friendly and cost-effective in terms of energy consumption. This combination of efficiency, performance, and size has made them the standard choice for powering modern computer systems and electronic devices.

Linear power supplies, while simpler, are generally bulkier and less efficient, especially at higher power levels, which is why they have become less common in general computer applications. Internal disk and non-volatile options do not pertain specifically to power supply types, making them irrelevant in this context.