How many threads are created when launching a JVM application?

When a JVM application starts, several threads are created by default, among which the main ones are:

• main — the main thread where the main method of your application runs.
• GC (Garbage Collector) threads — responsible for garbage collection.
• Finalizer Thread — a thread for executing finalize methods.
• Reference Handler Thread — handles weak, soft, and phantom references.
• Signal Dispatcher — handles OS signals.

The exact number of threads depends on the JVM implementation and configuration, but usually, there are about 5 to 10 threads immediately after startup. Additional threads are created as needed, for example, for thread pools, asynchronous tasks, etc.