How do the concepts of axis flow and lightweight flow relate in the context of multithreading?

In the context of multithreading in Java, the concepts of "OS thread" (operating system) and "lightweight thread" (lightweight thread) are related but not identical.

• OS thread — is a thread managed by the operating system kernel. Each such thread has its own stack, registers, and is scheduled by the OS. Creating and switching between OS threads are relatively expensive operations.

• Lightweight thread — is an abstraction that can be implemented at the JVM level or by a library, often called "green threads". They are managed within the process, do not require OS support, and can be more efficient for a large number of parallel tasks.

In a traditional JVM, each Java thread corresponds to an OS thread. However, modern implementations and frameworks (such as Project Loom) introduce lightweight (virtual) threads, which allow creating a vast number of parallel tasks with lower overhead.

Thus, lightweight threads are more optimized, JVM-managed threads, whereas OS threads are heavier, system-level execution units.