there are some reasons why TYPO3 copies every file into the well known uploads/pics/ folder that you “reference” in the backend in content elements. after copying the file there, it´s (ordinarily) protected from being deleted by the newb user or changes. if the editors changes stuff, the file is copied again after save with the _01 appendix. that leads to a bunch of issues like orphan files. theres some solution for that, but it is best to prevent that for good — if you like.
$TCA['tt_content']['columns']['image']['config']['internal_type'] = 'file';
that put into extTables.php or so sets that the file is used as is. the file is linked to where the user did upload it and no file reference is created.