Original: The regulatory sequence that is before (upstream (-), towards the 5' DNA end) the coding sequence is called 5' untranslated region (5'UTR), and sequence found following (downstream (+), towards the 3' DNA end) the coding sequence is called 3' untranslated region (3'UTR).
Simplified: The regulatory sequence that is before, or 5', of the coding sequence is called 5' untranslated region (5'UTR), and sequence found following, or 3', of the coding sequence is called 3' untranslated region (3'UTR).