Can one process have information about the actions of another process in the system?

In general, one process cannot directly obtain information about the actions of another process due to process isolation in the operating system.

However, there are methods of inter-process communication (IPC), such as:

• Using shared resources (files, databases).
• Sockets or pipes.
• Signals or special system calls.

In Node.js, message exchange between processes can be implemented via child_process or worker_threads.

If processes are not explicitly connected, one process does not have access to the internal state of another, except through system monitoring tools (e.g., reading logs, using OS APIs to gather statistics).

Therefore, for one process to know about the actions of another, it is necessary to organize data exchange or use OS mechanisms.