REST API vs. RESTful API

REST API

Definition

Representational State Transfer Application Programming Interface (REST API)

A REST API is an API based on the REST architecture.

Components of a REST API

1. URIs should use nouns rather than verbs and should be in lowercase.

Bad Example	http://eunhanspace.blogspot.com/Running/
Good Example	http://eunhanspace.blogspot.com/run/

2. URIs should not end with a slash (/).

Bad Example	http://eunhanspace.blogspot.com/test/
Good Example	http://eunhanspace.blogspot.com/test

3. Hyphens should be used instead of underscores.

Bad Example	http://eunhanspace.blogspot.com/hello_world
Good Example	http://eunhanspace.blogspot.com/hello-world

4. File extensions should not be included in URIs.

Bad Example	http://eunhanspace.blogspot.com/photo.jpg
Good Example	http://eunhanspace.blogspot.com/photo

5. Actions should not be included in URIs.

Bad Example	http://eunhanspace.blogspot.com/create-post/1
Good Example	http://eunhanspace.blogspot.com/post/1

RESTful API

Definition

RESTful refers to a system that follows the principles of REST. However, not all systems that use REST are RESTful.

A system can be considered RESTful if it follows the design rules of a REST API, and an API that performs all CRUD functions with POST or an API that does not follow the URI rules of a REST API can be considered a REST API but not RESTful.