What exactly is the difference between an external enclosure and a docking station? They seem to be very similar and serve the same purpose. Is it that the enclosure simply "encloses" the drive, while the docking station just allows it to be inserted openly (usually from the top)?
Is either one superior to use for copying files from a SATA drive? Would either one be faster than the other?
I've read that it's recommended for external enclosures and docking stations to have built-in fans, or to use a Thermaltake one. They do not have fans, correct? If the drive is connected for an extended period of time, would data transfer rates be improved if I have a fan?
"Is it that the enclosure simply "encloses" the drive, while the docking station just allows it to be inserted openly (usually from the top)?"
That just about sums up the difference between them, yes.
If you have several hard drives that you need to read from/write to at different times, then a docking station is obviously more convenient than having one enclosure which you have to keep opening up to swap drives, and it's less expensive than buying several enclosures.
Also, one docking station for say, 3 hard drives, only takes up one USB port. Whereas three separate enclosures need three USB ports. You might not have enough USB ports for that, so then you have to buy a USB hub, more expense. So you can see where a docking station can save you money as well as being more convenient.
Having a fan in an enclosure will not improve transfer rates at all, but it will keep the drive cooler and therefore less prone to heat-related problems such as bearing failure. I don't think a fan in a docking station is necessary though since the drives themselves are not actually enclosed in a small space, so heat can escape and air can circulate around them.
For what it's worth I use a hard drive enclosure with no fan. The enclosure is made of aluminium and I've no problems with the drive getting anywhere near too hot (I have it's temp monitored with software). The only reason I didn't buy a docking station is that I only need to connect one hard drive externally.