Process vs Thread — What's the Difference?

A process is an independent running program with its own memory space; a thread is a smaller unit of execution within a process that shares that process's memory with other threads in the same process.

Why they differ

• Processes are isolated from each other — a crash in one process doesn't directly affect another
• Threads within the same process share memory, making communication between them faster but also introducing risks like race conditions

How to choose

• Use multiple processes for isolation and fault tolerance, at the cost of higher memory usage and slower inter-process communication
• Use multiple threads when tasks need to share data efficiently and run concurrently within the same program

FAQ

Which uses more memory, a process or a thread?

A process, generally — each process needs its own separate memory space, while threads within one process share that same memory, making threads much lighter-weight to create.