The literature review can be defined as a selection of available documents

The literature review can be defined as a selection of available documents (published and unpublished) on the subject containing information, ideas, data and evidence written from a certain point of view in order to achieve certain goals or to express certain views about the nature of the subject matter and manner of investigation, as well as an effective assessment of these documents in relation to the proposed study (Hart, 1998). The need to review related literature is known as a thorough and in-depth insight into the effort published in this area. Relevant literature is an important step in getting a complete picture of what is being done concerning the issues being considered.