Once you've finished with it in LR you don't have to do anything, It's just sitting there indefinitely unless some catastrophy happens and your hard drive fails or something. ( use the backup function in LR and send it to a different hard drive) If you need to use it in some other application or something then you "export" it to wherever you want. Or if you want a smaller version you export that. Look over the export dialog box carefully. There are a lot of options that will allow you to do a lot of different things with a photo. Every time you export something check to be sure you have the appropriate boxes checked, etc. so the file goes where you want in the type, size, etc. you want.
It's a totally different concept than what you're used to, but it works well when you accept the difference.
Humm, I see Brad beat me out with a quicker and more detailed post. No shortage of help around here. A great place.