Web API (Application Programming Interface): A set of rules and protocols enabling seamless communication between different software components over the web
- Functions as a bridge between:
- Server: Hosts data and functionalities.
- Client: Consumes data and functionalities (e.g., web browsers, mobile apps, other servers).
Types of Web APIs
- Representational State Transfer (REST)
- Architecture: Stateless, client-server model.
- Methods: CRUD operations mapped to HTTP methods:
GET: Retrieve resources.POST: Create resources.PUT: Update resources.DELETE: Remove resources.
- Data Formats: JSON, XML.
- Strengths:
- Lightweight and platform-independent.
- Easy integration with modern applications.
- Simple Object Access Protocol (SOAP)
- Protocol: Formal, standardized.
- Messages: Encapsulated in SOAP envelopes, using XML.
- Transport: Supports HTTP, SMTP.
- Strengths:
- Built-in security and transaction management.
- Suitable for enterprise-grade applications requiring strict reliability.
- GraphQL
- Query Language: Single endpoint with flexible data fetching.
- Strengths:
- Eliminates over-fetching/under-fetching.
- Strong typing and introspection aid in API evolution.
Advantages of Web APIs
- Standardized Integration: Facilitates communication between diverse applications.
- Reusability: Exposes specific features or services for external use.
- Third-Party Services: Enables inclusion of functionalities like payments or logins.
- Microservices Architecture: Promotes scalability and resilience by decoupling monolithic systems.
Differences Between APIs and Web Servers
| Feature | Web Server | Web API |
|---|---|---|
| Purpose | Serve static/dynamic content (HTML, CSS, images). | Enable communication and data exchange between applications. |
| Communication | Uses HTTP to serve web browsers. | Can use HTTP, HTTPS, SOAP, or other protocols. |
| Data Format | HTML, CSS, JavaScript. | JSON, XML, or other structured formats. |
| User Interaction | Direct interaction via web browsers. | Indirect interaction via client applications. |
| Access | Typically publicly accessible. | Can be public, private, or limited to specific partners. |
| Example | Viewing a webpage via https://www.example.com. | A weather app fetching data from a weather API to display user-friendly information. |