Final answer:
Modern motherboards typically use either a 20-pin or 24-pin P1 power connector, with the 24-pin variant being more common in newer models.
Step-by-step explanation:
Modern motherboards use a 20-pin, or 24-pin P1 power connector. These power connectors are designed to supply various voltages to the motherboard, allowing it to function properly. The 20-pin connector was common on older ATX motherboards, while the 24-pin variant is found on newer ATX and Extended ATX (EATX) motherboards, offering additional power for PCI Express slots and other enhanced features.