This book is a guide for students who are studying econometrics as a course in their programme, There are 5 modules or units in this study material. The first unit explicate from the origin of econometrics, meaning, definition, need econometrics as a separate discipline, the scope of econometrics, Methodology of Econometrics, Reasons for introduction of stochastic error term, the difference between economic and econometric model and limitation. The second unit depicts about the simple linear regression in the aspects of its assumptions, derivations of its estimation of parameter value, properties and its technical note, applications of simple linear regression with examples. The third unit is the extension of simple linear regression as multiple regression with basic input with examples for applying in reality. The fourth unit briefly explains the violations of assumptions such as multicollinearity, homesecdasticity, autocorrelation, and specification errors in the aspects of causes, consequences, way of diagnostic the presence or absence and the remedies to rectify the issues. The fifth module or unit introduces about the qualitative response models with dummies, distributed lag models with importance’s of lag, analysis of variance, analysis of covariance, comparison of analysis of variance and analysis of covariance. The last unit attempted to explain about the free open source software Gretel to apply in need of finding solution to an economic phenomenon. The Glossary is attached in the annexure for a better understanding the terminology of econometrics which will support to face multiple choice questions of any competitive examinations in national and state level. In Simple words, this book is a guide to get the knowledge of econometrics and apply the same into reality wherever necessary.