Abstract
In this thesis, we first review some aspects of holographic entanglement entropy. We mainly consider the prescriptions that are called RT prescription, covariant HRT prescription and QES prescription. We next review how RT, HRT, and the static case of QES prescriptions can be reformulated in terms of bit threads. In the last chapter, we propose a definition for quantum covariant bit threads and give incomplete proof that it is equivalent to the QES prescription.