Data classification is the categorization of data for its most effective and efficient use. Data can be classified according to any criteria, not only relative importance or frequency of use. Classification can help an organization to meet legal and regulatory requirements for retrieving specific information within a set timeframe, and this is often the motivation behind implementing data classification methods and algorithms. The paper contains brief discussion of various classification methods that includes decision trees, K-nearest neighbor classifier, na?ve bays classifier and neural network. The paper also discusses some applications of classification model and at the end the paper is concluded with the brief observations of these classification models.