Related Post - https://www.nairaland.com/3267973/gaming-pc-what-need-know

Here's what you need to know about the power supply connector.

24-pin (20+4 pin) - this is required to supply power to your motherboard. This can be split if your motherboard only has a 20-pin ATX.
8-pin (4+4 pin) - supplies power for the CPU. This can be split if your motherboard only has a 4-pin CPU power connector
8-pin PCIe (6+2 PCIe) - supplies power to the graphics card. This can be split if your graphics card only has 6 pin. Most PSU's will ship with 2x 8Pin as some graphic cards require 1x 8pin+ 1x6-pin or 2x 6-pin
SATA connector - to power your 2.5" SSD/HDD or 3.5" HDD and CD/DVD/Bluray drive.
Molex connector - powers peripherals like case fans, fan controller, in some cases with an adapter, the graphics card.

Ok, there isn't one for a floppy drive, but who the heck uses floppy drives?

Don't attempt to connect the 8-pin PCIe to the motherboard, it can damage your system.
The 24-pin ATX connector and 8-pin CPU connector both plug into the motherboard