Data Mining is a technique for organizing, analyzing and making decisions with raw data. Statistical data analysis plays a vital role in understanding and decision making. However analysis can be made using a technique called Clustering in data mining. Clustering is grouping or segregating a large data set into small groups for analysis. Clustering is used in various fields like image recognition, database management system, data analysis, augmented reality etc. This paper gives a review of the steps involved in converting a raw data into a knowledgeable data set, types of clustering and different stages involved in clustering. Also this paper involves a complete study of clustering with all the techniques and comparisons involved between different techniques. This study will be helpful for people to select a specific method and apply it for suitable environment.