P8 and P9
P8 and P9 power connectors
There are no differences between the power connector of an AT motherboard versus that of a BabyAT motherboard.
The case, motherboard, and power supply must all be the same form factor. Obviously the motherboard and the case would have to be the same or the motherboard would never fit in the case. Then the power supply must not only fit in the case, but have the same connectors as the motherboard. Otherwise it won't work.
In a motherboard, VCC (Voltage Common Collector) is typically connected to the power supply through designated power connectors, such as the 24-pin ATX connector and additional CPU or GPU power connectors. Ground connections are usually made through the same power connectors, as well as various ground pins located throughout the motherboard. It's essential to follow the motherboard's manual for specific connection points to ensure proper power distribution and system stability.
The "form factor."
The main power connector 20-24pin. One for the CPU 4-8 pin. PCI express 4 pin. It's depend on what type of motherboard do you have. But commonly, new motherboards uses 2 power cord P8 and P9.
The mother board, power supply, and chassis
Case: minitowers:compact cases,low-profile cases or slimline cases. Power supply: ATX power supply
The atx 12 connector is one of the motherboard power connectors and used for 12 volt power connect for cpu voltage regulator.
If you are refering to the 20 or 24 pin molex connector, this is the motherboard power distribution subsystem from the power supply. If you are refering to the several other small connectors, they have various functions. Front panel indicators and switchs, USB distribution connectors, fans, CD audio, etc.
If it as a 20 or 24 pin connector and a 4 pin connector then it is a ATX power supply.