REST promotes CRUD. CRUD is for databases, not applications.
Databases generally have four operations to a set of data: Create, Read, Update, and Delete; these four operations are known by the acronym CRUD. An SQL-based relational database (like PostgreSQL, MySQL, etc.) have 4 cooresponding statements:
- Insert -> Create
- Select -> Read
- Update -> Update
- Delete -> Delete
The CouchDB database and SOLR search engine operate natively over a REST interface. Your applications perform CRUD operations on these data stores by employing the above style of request.
Architectures based on REST, like Ruby on Rails, builds the application on table resources to perform CRUD operations. By doing this, we get a free API into the application callable from any platform capable of making HTTP/REST calls.