I was a Windows guy, who moved over the Mac but only recently started saving things to the Mac file system (on my Macbook Pro). On a Windows computer, I can plug in any external hard drive I have here and slide over folders of info on to it, easy peazy. If they are large, it's just a matter of waiting. Now with the same external hard drive (never reformatted from new, I just delete the folders of WD Passport stuff that was on it, assuming it was all tracking or ads or trying to get me to sign up for something. (done this a long time ago). Anyway, can I just use that external hard drive like it is, and plug it into a Mac and slide all my stuff that I put in one folder on my desktop over to the external hard drive? Is there any file name/size/style/type/format that is different, or that I need to prepare the external hard drive for...? Probably a silly question, but I don't want to mess up the files (some .stl files, mostly photos) so I thought I'd ask first. Thanks!