Webhook vs. Websocket: What's the difference?
Webhooks and websockets are two different types of communication protocols. They each have their place depending on what you're trying to accomplish.
Webhooks are sort of a reverse API, or server to server push notifications. It's how servers notify each other of events, and enable servers to update each other asynchronously in real time. They work by sending out an HTTP request to a specified endpoint when an event is triggered. This makes webhooks ideal for integrating two applications. You can trigger actions in one app based on events in the other app.
Webhooks are very versatile, and how they are used varies greatly depending on the application. For example, they can be used to send notifications when a message is received, a payment is sent, or any other type of update. They are a way to get data from a third party back into your own system.
Websockets are a type of communication protocol that provides full-duplex communication channels over a single TCP connection. While webhooks send information from one server to another, websockets create a two way communication channel.
You'll generally see websockets used to send communications from one part of an app to another. For example, many instant messaging applications use websockets to send and receive messages between the user and server. In the chat example, there would be a separate websocket connection for each user to send and receive messages.
When to use Webhooks (and when not to)
Webhooks are an extremely efficient communication method when appropriate. Webhooks are the perfect solution when you want one-way event driven communication between two servers.
A popular example of webhooks is Discord bots. A common use case for webhooks in Discord is a bot to automatically post in a channel when a specific Twitter account sends a tweet. This is an excellent use case for webhooks as you want the post to happen right away (real time), only when someone sends a tweet (event driven), Twitter doesn't need a response (one way), and only the bot needs to receive the information (one to one).
When to use Websockets (and when not to)
Websockets are very useful for interactive and real-time browser applications. A good example would be a navigation system. The client needs to receive directions from the server while the server needs the client's location to generate the directions.
While webhooks and websockets are both ways for applications to communicate, which to use depends a lot on what you're trying to achieve.
Webhooks are great for async notification of eents between servers. This makes them very useful for integrating two separate applications.
Websockets are generally used to send communications within a single interactive application.