This document summarizes Chapter 7 from the textbook "Operating System Concepts - 9th Edition" which covers deadlocks in computer systems. It defines the four conditions required for deadlock, characterizes deadlocks, and presents various methods for handling deadlocks including prevention, avoidance, detection, and recovery. Prevention methods restrain how processes request resources to ensure deadlock cannot occur, while avoidance methods dynamically determine safe resource allocations to guarantee no deadlocks. Detection finds and recovers from existing deadlocks.