What does preparing to copy mean?

I'm trying to copy a large amount of files from a hard drive to a time capsule. Around 200 GB. Normally copying files in OSX is quite fast and simple, but I found this unmanageable, as before it starts copying it prepares to copy the files, And the number of files to copy slowly increases.

Normally this stage is over in the blink of an eye, but because of the large volume it took more than 20 minutes, I gave up after that. What exactly is it doing in this time? Why does it need to do that, when I'm simply copying one folder (there is just one folder in the root level of the hard drive) so it knows that all the files are in there.

Is there anyway to skip this process, as it is actually faster, although more time consuming for me, to copy smaller chunks of it, one after the other?

Why can't it just copy all the 1s and 0s across without any of this preparing?

Not sure what the 'preparing' stage actually does. I suspect it could have something to do with verifying that the destination doesn't have files/folders that are present in the source (leading to it having to ask you what to do about the conflict).

In either case, if you are comfortable with Terminal, you can use rsync which begins copying immediately and gives you feedback right away.

I would use something like:

rsync --partial --progress -av ~/Desktop/MyFolder /Volumes/MyTimeCapsule/