The video explains the workings of a finalizer method, detailing how it can lead to OutOfMemoryError. It offers insights on identifying the root cause when the finalizer thread becomes stuck and provides troubleshooting tips using fastthread.io to resolve these issues effectively.
Non-daemon threads, or user threads, prevent the JVM from exiting if alive, while daemon threads do not. Daemon threads should be used cautiously, as they can lead to resource leaks if the JVM halts mid-execution, skipping finally blocks. Most JVM threads are daemon threads, inheriting from parent threads.
The content discusses how transitive blocking among threads can render applications unresponsive. A real-world example from a travel application illustrates this, where a thread was blocked by another, causing a complete halt for 42 threads due to a bug in an APM monitoring agent. Upgrading the agent resolved the issue.