Copy Paste/Replace works the same way but you get more options than windows if I am not mistaken. Don’t overwrite and check “apply to all”. I think that’s what you’re looking for.
This will move all the files that aren’t duplicate names, but leave the others in the original folder. Then you can go through and check as you would on windows. You can turn on the preview on the icons so you don’t have to open each one to see if it is a duplicate.
There are also various programs for Mac (and probably Windows as well) that will detect duplicate photos automatically, I found one recently, sorry though I can’t remember the name. If you google for it you can probably find one.
Also–OSX comes with a great Photo organizing app called iPhoto. If you just drag all of the icons directly into iphoto, nothing will be overwritten and you can delete duplicates easily. (all photos will show up at once)
Hope this helps if you ever have a problem like this again.