How to distinguish a process from a thread in an operating system?

A process is an isolated execution unit with its own address space, resources, and state. A thread is the smallest unit of execution within a process, sharing memory and resources with other threads of the same process.

Main differences:

• Processes are isolated from each other, threads within a process share memory.
• Creating a process is heavier and slower than creating a thread.
• Threads allow for parallel execution of tasks within a single process, which is more efficient for shared data.

For example, a web server can run separate processes to isolate clients, and within each process, use threads to handle requests in parallel.