This Paper Presents the Brief Overview on Congestion In Power System, Its Causes, Effects and Remedies. It Also Deals With Congestion Management. Congestion Management Is a Significant Feature of Power System. In Power System, When Power Flows Through Transmission Lines and Transformers Exceeds the Power Transfer Capability of Transmission Lines, Congestion Takes Place. Reactive Power Is One of the Key Factors For Controlling Congestion In Transmission Lines. It Is Mainly Provided By Regulating Tap Changing Transformers Shunt Capacitors and Generators Excitation. Flexible Ac Transmission System (Facts) Devices Are Another Effective Means of Controlling Reactive Power Flow In Transmission Lines. They Change the Reactance Across the Transmission Line By Using Fast Acting Power Electronic Switches Along With Inductors and Capacitors. As a Result, Line Loadability Increases, System Losses Decline, Power System’S Security Enhances and Overall Cost Reduces. This Paper Also Gives a Brief Literature Review on Finding Optimal Location For Placing Facts Devices.