What is the difference between executing a separate thread and a full process in an operating system?

A process is an isolated execution unit with its own address space, resources (files, memory, descriptors), and system data. Each process operates independently and does not share memory with other processes.

A thread is an execution unit within a process that shares the same address space and resources with other threads of the same process. Threads are easier to create and switch between than processes but require synchronization when accessing shared data.

Key differences:

• Isolation: processes are isolated, threads are not.
• Resources: processes have their own resources, threads share resources.
• Performance: switching between threads is faster than between processes.

Example in Python using threads:

import threading

def worker():
    print('Thread is running')

thread = threading.Thread(target=worker)
thread.start()
thread.join()