Add to ORKGU ovom je radu dan pregled jednodimenzionalnih i dvodimenzionalnih kodova počevši od prvog barkoda. Kronološki je opisan razvoj i unapređenje barkodova, njihova struktura i namjena. Posebna je pozornost posvećena dvodimenzionalnim kodovima gdje prednjači QR kod. Obrađen je problem sigurnosti istoga, kao i današnjih alternativa QR kodu.In this work, the review of one-dimensional and two-dimensional codes are given starting from the first barcode. The development and advancement of barcodes are described chronologically, as well as their structure and purpose. Special attention is dedicated to two-dimensional codes where QR codes are dominant. Security problems related to QR codes are stated and described, as well as alternatives to QR codes