Concurrency
ELI5 — The Vibe Check
Concurrency is juggling multiple tasks at once — not necessarily at the exact same instant, but switching between them fast enough that they all seem to be happening simultaneously. One chef, multiple dishes being worked on in turns.
Real Talk
Concurrency is the ability of a system to handle multiple tasks in overlapping time periods. It doesn't require true parallelism — a single CPU can be concurrent by interleaving tasks. Async/await, event loops, and coroutines are concurrency mechanisms.
When You'll Hear This
"Node.js handles concurrency via its event loop, not threads." / "We need concurrency to handle thousands of simultaneous requests."
Related Terms
Async
Async means 'don't wait around'. You order food at a restaurant, then chat with friends instead of standing at the kitchen window staring.
Deadlock
A deadlock is when two things are each waiting for the other to go first, and neither ever does. Thread A holds Lock 1 and wants Lock 2.
Parallelism
Parallelism is doing multiple things at literally the exact same time — two chefs cooking two dishes simultaneously.
Process
A process is a full running program with its own isolated chunk of memory.
Race Condition
A race condition is when two parts of your code are racing to do something at the same time and the winner isn't guaranteed — leading to unexpected, hard-t...
Thread
A thread is a mini-worker inside your program that can run tasks independently.