Webhook, API & SDK

An API lets two systems exchange data on request; a webhook lets a system push data automatically the instant an event happens; an SDK is a packaged toolkit for building an integration with a specific platform.

The practical difference between an API and a webhook is who initiates the exchange: with an API, your system asks another system for data ("give me this user's last 10 orders"); with a webhook, the other system tells yours the instant something happens ("this order just shipped") without being asked. Real-time integrations (a Slack alert the moment a high-value customer signs up) almost always rely on webhooks; batch reporting jobs usually rely on APIs.

An SDK (Software Development Kit) is a pre-built package of code — for a mobile attribution provider, an analytics tool, an ad network — that handles the technical plumbing of an integration so a development team doesn't have to build the raw API calls from scratch.