External beam radiotherapy is one of the main methods of cancer treatment in curative and palliative oncology. It aims at precise delivery of high dose to a target volume, which is performed in a series of defined fractions by a linear accelerator. To ensure the effectiveness of the therapy and the safety of the patient, high reproducibility of the patient position is mandatory. In this paper, we review patient positioning techniques and compare their technical principle, system components, application in workflow, general advantages and drawbacks. Furthermore, we explore future potential for the implementation of digital tools.