??

I don't know if the original poster will see this or not, but maybe it will be handy for someone else.

Having two identical websites can cause problems for Google search ranking and such, so it should be avoided. I believe it's an exception if it's different TLD (top level domain) extensions (i.e. having mywebsite.com and mywebsite.co.uk the same, as Google guesses it belongs to the same person).

If someone else has copied your website though, probably asking them to take it down should be the first step, and if they refuse, do a DMCA takedown.

If you have somehow made a duplicate of your own website, there are several things that could mean, but generally, it would just be because you uploaded it twice with slightly different filenames. If so, check on the server you are using and see if you can find any duplicate files, and delete one (but probably back everything up first, just in case).

I hope this is helpful and I didn't totally misunderstand the question.