SATA II is the second-generation version of SATA, and the main difference is that the maximum speed of data transfers can be faster. It is backwards-compatible: any SATA II controller can handle any SATA or SATA II device. Cables are unchanged. The only compatibility issue that MIGHT come up is trying to use a newer SATA II HDD with an older SATA controller, and there are ways to make that work if it does not do it automatically for you.
ATA drives also are known as IDE or PATA, and they are NOT compatible with SATA systems directly. However, most current computers have BOTH SATA ports and IDE ports on the mobo's so you can use both device types. Although 2 IDE ports were common on mobo's (those can handle max 2 IDE devices per port with the right ribbon cable), some have only one, and some of the newest have none.
As to "dated": SATA II is very current. the first SATA III (they won't really be called that!) units are just starting to appear, and not much of that is actually on the market. It's the original SATA (1?) that has almost disappeared from the market.