Data mining is a process which finds useful patterns from large amount of data. It is a powerful new technology with great potential to help companies focus on the most important information in their data warehouses. It uses machine learning, statistical and visualization techniques to discovery and present knowledge in a form which is easily comprehensible to humans. This paper of literature focuses on data mining techniques, trends, issues, tools, crucial concepts and applications. In this paper, the authors have focused a variety of techniques, approaches and different areas of the research which are helpful and marked as the important field of data mining technologies.