How does a process differ from a thread?

A process is an execution environment with its own virtual address space and operating-system resources. Threads within a process share that address space and many resources while maintaining their own stacks, registers, and scheduling state. Sharing makes communication convenient but introduces races and synchronization needs. Separate processes provide stronger memory isolation, although they can communicate through explicit IPC or shared memory. Exact resource ownership varies by operating system. A crash in native code can terminate the whole process, including its other threads.