ultra ata vs. ata

I'm trying to replace my hd on my powerbook g4, and of course the hd requires a basic ata connection. so, does that include ultra ata connections too? if i go out and buy an ultra ata hd, will it be fully compatible with my powerbook g4?

I'm not sure what you mean by ultra-ata; I'm guessing you mean UltraDMA, which all modern hard disks use anyway. The connectors are all exactly the same and all controllers can use UDMA drives even if they don't support UDMA themselves because the drives are backward compatible. Any drive over about 10GB will be UDMA.

ata, and uata, and udma all have to do with data handling, and speed. Which is all pretty much standard across the board.

The connection port is what you are asking about, 2.5" IDE drive is what you want. like this one IDE is the name of the interface

Ultra-ATA drives are just the 133Mb speed instead of the normal 66/100, but in any event they are backwards compatible so it doesn't matter. Any IDE hard drive will work in your Powerbook, whether it be Ultra-ATA or regular ATA. Just make sure you don't get a SATA drive because that will not work in a PB.