What are HTTP methods?
HTTP is a request-response protocol between a client and a server.
HTTP methods indicate what action should be performed for requesting a specific resource.
These methods are also called HTTP verbs. The resource is the noun.
CRUD refers to the ways that stored data can be operated. It also refers to the four basic functions of persistent storage and maps to the four major HTTP methods (see below).
HTTP request methods can be considered:
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Safe, if they do not alter the state of the server (read-only operation).
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Idempotent, if an identical request can be made (once or more) without changing the original result (i.e., no side effects).
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Cacheable, if they can be cached (stored for retrieval), saving a new request to the server.
HTTP Methods
GET
Read / request data from a resource.
Safe / idempotent / cacheable
POST
Create a resource.
Not safe / Not idempotent / Not cacheable
PUT
Update a resource.
Not safe / Idempotent / Not cacheable
DELETE
Remove a resource.
Not safe / Idempotent / Not cacheable
HEAD
Read / request data (same as GET) from a resource but without a response body.
Safe / idempotent / cacheable
PATCH
Apply partial modifications to a resource.
Not safe / Not idempotent / Not cacheable
OPTIONS
Describe the communication options for a resource.
Safe / Idempotent / Not cacheable
CONNECT
Establish a tunnel to the server identified by a resource.
Not safe / Not idempotent / Not cacheable
TRACE
Perform a message loop-back test along the path to a resource.
Safe / Idempotent / Not cacheable