Serial ATA is the connection/connector interface, ATA-8 is the protocol on that interface.
IDE was the interface and it also used an ATA protocol for communications.
IDE and ATA are not the same things, just as SATA and ATA are not the same.
To be clear, IDE defined that a drive should have Integrated Device Electronics (I.e. a controller) onboard and communications with the host should be done according to the ATA specifications.
While IDE and ATA are incredibly closely related, they are not the same thing.
IDE has been back-acronymed as PATA as the interface was a parallel connection using the ATA standard. SATA is a Serial ATA connection.