What is the difference between a process and a thread?

A process is an instance of a running program that has its own address space, system resources (files, sockets, etc.), and is independent of other processes. A thread is a unit of execution within a process that shares memory and resources with other threads of the same process but has its own stack and execution context.

Main differences:

• Processes are isolated from each other, while threads within the same process are not.
• Creating and switching between processes is more resource-intensive than between threads.
• Threads allow parallel execution of tasks within a single process, sharing data.

Example: a web server can run multiple processes for isolation, and within each process, several threads can handle requests in parallel.