This document provides an introduction to smart grids. It defines a smart grid as an electricity network that intelligently integrates generators and consumers to efficiently deliver sustainable, economic and secure power. The document outlines the historical development of grids, the functions and features of smart grids, and opportunities they provide like integrating electric vehicles and renewable energy. It also discusses barriers to smart grids like cost and technology integration challenges. Benefits over conventional grids include active consumer participation and optimization of resources. The document concludes by discussing India's smart city projects and how smart grids can help reduce carbon emissions.