In the past, PATA hard disks were referred to as Integrated Drive Electronics (IDE) or Advanced Technology Attachment (ATA) hard  disks. So, PATA = IDE = ATA

This technology allows the disk to be configured in one of four different configurations:

• Primary master PATA hard disk (linux name: hda)
• Primary slave PATA hard disk (linux name: hdb)
• Secondary master PATA hard disk (linux name:hdc)
• Secondary slave PATA hard disk (linux name:hdd)