Needless files…

I have edited the default wordpress theme to make my own theme for my site and I’m wondering what files I really need to keep.

These are the files in question:

archives.php- (not archive.php)
what does this file do? it appears as if it displays a list of all the archives on one page but I can’t find a way to access it online.

comments-popup.php-
What does this do? I also cannot find a way to access this page online.

Theme Functions (functions.php)-
Is is this necessary only for the default theme? or does it do things for any wordpress page?

image.php-
what is it and how do i access it online?

links.php-
how do i access it online? i can’t seem to find a link or anything.

I know that’s a lot of files, but any help would be great, even if it’s only about one file.

thanks in advance!