Difference between a process and a thread.

A process is an instance of a program that is executing within an operating system, possessing its own address space, resources (files, memory), and execution threads.

A thread is a unit of execution within a process. Multiple threads within the same process share the process's memory and resources but have their own stack and registers.

Main differences:

• Isolation: processes are isolated from each other, threads are not.
• Resources: a process has its own address space, threads share the address space of the process.
• Creation: creating a process is heavier and slower than creating a thread.
• Communication: inter-process communication (IPC) is more complex than communication between threads.

Example: a browser can run each tab in a separate process for isolation, and use multiple threads within a tab for parallel tasks.