Explain the occurrence of a deadlock giving an example?

A deadlock occurs in a multi-threaded or multi-process system when two or more processes are waiting for each other to release a resource that they need in order to proceed. This results in a situation where none of the processes can make progress, leading to a deadlock.

For example, consider a scenario where two processes, Process A and Process B, each hold a resource that the other process needs to complete its task. Process A is waiting for a resource held by Process B, and Process B is waiting for a resource held by Process A. In this situation, neither process can proceed because they are both waiting for the other to release the resource they need.

Deadlocks can be avoided by carefully managing the allocation and release of resources, using techniques such as resource allocation graphs, deadlock detection algorithms, and resource ordering.