What is the difference between polling and webhooks?

Question

Accepted Answer

**Polling** — client requests repeatedly. **Webhooks** — server pushes events.

**Polling:**
- Client initiates requests.
- Regular intervals.
- Wastes bandwidth if no updates.
- Simple implementation.

```
Polling:
Client → Is there data? → Server
Client ← No ← Server
Client → Is there data? → Server
Client ← Yes, here it is ← Server
```

**Webhooks:**
- Server initiates requests.
- Event-driven.
- Efficient, no wasted requests.
- Requires endpoint setup.

```
Webhooks:
Client registers URL → Server
Server: Event occurred! → POST to URL
(Server pushes when event happens)
```

**Key differences:**
- **Polling** — client-initiated.
- **Webhooks** — server-initiated.
- **Polling** — periodic.
- **Webhooks** — event-driven.

Systems Analyst: What is the difference between polling and webhooks?