What are the main advantages and disadvantages of using Green Threads in application development?

Green Threads are threads managed not by the operating system, but by a virtual machine or runtime (e.g., the language runtime). In Go, these are called goroutines, which are implemented at the language and scheduler level.

Advantages of Green Threads:

• Lightweight: created and switched faster than system threads.
• Scalable: thousands or even millions can run concurrently.
• Managed by language runtime, optimizing concurrency.

Disadvantages:

• Do not directly utilize multi-core capabilities unless mapped to OS threads.
• Blocking system calls can block all green threads if not handled asynchronously.
• Debugging and profiling can be more complex.

In Go, goroutines are an example of efficient green threads, scheduled by the runtime for writing concurrent code with simple syntax.