I just ordered this harddrive (seen above) and I was wondering if I can properly transport files with it. Both of my Internal Harddrives are ATA but it mentions an eSATA connection is compatible with the external HD. Does this mean that my external HD won't be able to copy files from my ATA drives???
I am gonna oversimpliify this but eSATA is just another external connection format just like USB and Firewire. You should have no problem at all. Your computer takes care of transmitting between different devices. Many computers have an IDE (aka PATA) CD drive and an SATA HD internally. All the computer cares about is can it get the data from the device to the computer itself (whether PATA, SATA, USB, Firewire, SCSI, LPPT, Serial Port so on). From there it takes care of sending it to where it needs to go and in what format. In your case you just need to make sure you have the connection you need to connect your hard drive to the computer (either USB (essentially all computers have this) or eSATA (faster but more rare)).
If you want some technical information, this functionality is often the resposibility of the North Bridge and south bridge chips (the other ones that have heatsinks on them). The north bridge is usually resposble for transferring data to the RAM, the CPU, the PCI/PCIe cards and the network and the south bridge. The south bridge is often the USB ports, the Hard drive and peripherals and sometimes some of the PCI/PCIe slots. These chips are called bridges for a reason, they bridge different interfaces on the computer that often times use completely different data formats. These chips input the data, change the data type, then output it. This is a simplistic view as they also control speed and all sorts of other complex stuff, but this is a rough view.