This book describes the whole content of the thesis project titled "Data Loss/Leakage Prevention" in organizational perspective which mainly involves in minimizing the data loss or leakage prevention. The project was carried out during the master program at Lulea Tekniska Universitet, which is called master thesis. This is an ongoing project in a company and was did by two researchers where one researcher who worked for a company have collected real time data's, conducted interview questionnaires, and the other researcher collected data's through video conferencing and email management system. In this book, the researcher deals with both the terms data loss and data leakage in analyzing how the DLP technology helps in minimizing the data loss/leakage problem? The objective of the research is that as organization was facing issues with data loss, so the project was dealt with analyzing a research question on evaluation of how well DLP fills security gap in comparison with previously used technology (such as Firewall, IDS, IPS etc.) in a motive to solve data loss/ leakage problem.