This paper deals with detail study of Data Mining its techniques, tasks and related Tools. Data Mining refers to the mining or discovery of new information in terms of interesting patterns, the combination or rules from vast amount of data. It helps in classifying, segmenting data and in hypothesis formation. With such a vast amount of data, there is need for powerful technique for better interpretation of these data. Including commercial and open source, many program available to perform data mining. Data mining tools predict future trends and behaviours, allowing business to make proactive and present knowledge in the form which is easily understood to human.