What are the differences between a thread and a process in Unix-based systems?

In Unix-based systems, a process is an instance of a running program with its own address space, set of resources (file descriptors, environment variables, etc.), and an identifier (PID). A thread is a unit of execution within a process that shares the process's address space and resources with other threads of the same process but has its own stack and registers.

Main differences:

• Address space: processes are isolated, threads share the process's memory.
• Resources: processes have their own resources, threads share the process's resources.
• Creation: creating a thread is usually faster and less costly than creating a process.
• Context switching: switching between threads is faster because it does not require changing the address space.

Example: in Go, goroutines are lightweight threads that operate within a single process.