API (Application Programming Interface)
- APIs are interfaces that allow different software applications to communicate and interact with each other.
- Diverse Types: Includes various types like SOAP, RPC, and REST.
- Multiple Protocols: Can operate over a variety of protocols, not just HTTP.
- Varied Data Formats: Supports multiple data formats like XML, JSON, and others.
- Wide Application: Used in web services, operating systems, databases, and even hardware interfaces.
REST API (Representational State Transfer API)
- Specific Type of API: A subset of APIs that specifically adhere to REST architectural principles.
- HTTP/HTTPS Based: Operates exclusively over HTTP/HTTPS protocols.
- REST Principles: Follows REST principles like statelessness, uniform interface, and client-server architecture.
- Common Data Format: Primarily uses JSON for data exchange, but can also support XML and plain text.
Web Services Oriented: Mainly used for web services, especially for web-based applications and cloud solutions.
SOAP API (Simple Object Access Protocol API)
- Uses XML as the message format and typically operates over protocols such as HTTP, SMTP, or more.
- Complex Standards: Enforces a set of rigid standards for message format and communication, including XML Schema for message structure and WS-Security for message-level security.
- Stateful Operations: Can support both stateful and stateless operations, allowing for more complex interactions between client and server.
- Standards-Driven: Adheres to specific standards like WS-*, including WS-Addressing, WS-ReliableMessaging, etc.