The old IDE hard drives all used a 4-pin Molex power connection from the PSU. In terms of data connection schemes, those units were called variously IDE or PATA drives. Most of today's drives use the SATA data interface system. But in terms of power supply connections, the older ones all use the Molex connector, whereas the new ones just use the name SATA to describe its new design power connector as well as the same term for its data connector - even though they are different connectors!
The older Molex connector output from the PSU became very widely used for things other than IDE hard drives - things like CD drives, DVD drives, fans, backup tape drives, etc. So they became known more generally as Peripheral power outputs, rather than 4-pin Molex outputs. Some of the modular cable sets that came with your PSU and fit into one of those 6-pin Peripheral / SATA sockets have on their wires both older 4-pin Molex (aka Peripheral) female connectors and SATA power connectors. You can use both types as required by your devices. Often today one finds there is a shortage of SATA outputs, and some unused Molex outputs. For that you can get little adapters to convert a Molex to a few SATA power outputs for easier use.