The ongoing fast pace research in hardware and software technology has resulted in memory devices efficient and faster than ever before. However, the issue of security of the contained data is rarely discussed. There is an evident capability of these devices to retain data even when it is erased. In this thesis, a study is conducted to qualitatively analyze the extent to which data deletion is important and why secure deletion should be applied. Afterwards, following the sequential exploratory procedure, this paper presents an analysis of methods used to recover the data after being deleted in addition to the techniques used to securely delete this data. Based on this study, some recommendations are made to ensure the safety of data.