d there is only one track, none of the trains can move once they are in front of each other. Similar situation occurs in operating systems when there are two or more processes hold some resources and wait for resources held by other(s). DEADLOCK CHARACTERIZATION: In a deadlock, processes never finish executing, and system resources are tied up, preventing other jobs from starting. Before we discuss the various methods for dealing with the deadlock problem,we look more closely at features that characterize deadlocks. 1. Mutual Exclusion 2. Hold and Wait 3. No preemption 4. Circular Wait METHODS FOR HANDLING DEADLOCKS: 1. Deadlock Ignorance 2. Deadlock avoidance 3. Deadlock detection and recovery