[bascule]

You're confusing concurrency and parallelism. Node is a single-threaded event loop. It can only do one thing at a time. Node can perform many operations concurrently, but they're not running in parallel. If any one operation blocks, the whole event loop stalls.

Parallel execution requires multiple threads running on multiple CPU cores. Node requires multiple VMs to do this.

[meryn]

Thanks for explaining difference between concurrency and parallelism so clearly! I'll remember this.

I of course realize that Node doesn't truly handle things in parallel. It's a single thread, after all.