I’ve had a few clients ask this question and this Reddit answer is the most succinct definition I can give:

In more detail, if you think of an API like a restaurant menu of all the options of data you could retrieve and functions you can do.

1. You initiate the request (“I’ll have the burger, please”)
2. You get an immediate response (your food)
3. You can order whenever you want
4. But you have to keep asking if you want updates (“Is my order ready yet?”)

You check a weather app. The app calls the weather service’s API asking “What’s the weather in Houston?” and gets back “75°F and sunny.”

Direction:

• API: You ask → Service responds (Pull)
• Webhook: Service tells you when something happens (Push)

Timing:

• API: Real-time, on-demand (“What’s happening NOW?”)
• Webhook: Event-driven (“Tell me WHEN something happens”)

Efficiency:

• API: Can be inefficient if you’re constantly checking for updates
• Webhook: Efficient for notifications – no wasted checks

The Crossover

They often work together! Here’s a common WordPress/LMS scenario you might relate to:

1. Someone enrolls in your LifterLMS course (triggers a webhook)
2. The webhook notifies your email system
3. Your email system uses an API to get more student details
4. Then sends a personalized welcome email

Another example with WooCommerce:

• Webhook tells you “Order placed!”
• You use the API to fetch full order details
• You use another API to update inventory
• A webhook later notifies you “Payment confirmed!”

When to Use Which?

Use APIs when:

• You need information on-demand
• You want to retrieve specific data
• You’re building interactive features

Use Webhooks when:

• You need to know when something happens
• You want to automate reactions to events
• You’re syncing systems in real-time