What is API?
An Application Programming Interface (API) is a set of rules and protocols that enables different software applications to communicate with each other. APIs define how requests are made and responses returned. REST APIs are the most common standard on the web and use HTTP methods (GET, POST, PUT, DELETE). Examples of APIs: Google Maps API (embed maps), Stripe API (payments), OpenAI API (AI features), social media APIs (fetch posts). For websites, APIs are important for integrations: CRM connection, payment providers, newsletter tools, headless CMS, and more.
Key Points
- REST APIs use HTTP methods (GET, POST, etc.)
- JSON is the most common data format
- API keys for authentication and access control
- Rate limits restrict requests per time period
- Documentation is crucial for integration
- Webhooks for real-time notifications
Practical Example
“Via the HubSpot API, new contact requests are automatically created as leads in the CRM.”