Http methods and Codes

What is the HTTP?
The Hypertext Transfer Protocol (HTTP) is the foundation of communication between clients and servers on the web. HTTP methods play a crucial role in defining how this communication occurs. Each method has a specific purpose and understanding their nuances is essential for effective web development.

What are HTTP Methods?
HTTP methods, which are also known as HTTP verbs, are responsible for defining the actions that can be performed on resources identified by Uniform Resource Identifiers (URIs)

HTTP defines several methods, each serving a specific purpose in handling resource requests and responses. The most common HTTP methods include: GET, POST, PUT, DELETE, HEAD, OPTIONS, CONNECT, and TRACE. The GET method retrieves information from the server, while the POST method sends data to the server to create, update, or delete resources. The PUT method is used to update a resource, and the DELETE method is used to delete a resource. The HEAD method retrieves only the header information of a resource, while the OPTIONS method retrieves the available methods that can be used on a resource. The CONNECT method establishes a network connection, and the TRACE method echoes the received request back to the client.
GET Method:
The GET method is one of the simplest and most commonly used HTTP methods. It is used to request data from a specified resource. GET requests are idempotent, meaning multiple identical requests should have the same effect as a single request. The data is included in the URL as parameters. Requests using GET should only retrieve data.

Example:

POST Method:
POST is used to submit data to be processed to a specified resource. Unlike GET, POST requests do not append data to the URL; instead, they include the data in the request body. This makes it suitable for sending large amounts of data or sensitive information. The POST method is used when you want to send some data to the server, for example, file update, form data, etc. The POST method often causes a change in state or side effects on the server.

Example:

PUT Method:
PUT is used to update a resource on the server. It requires the client to send the entire updated resource representation. If the resource does not exist, PUT can create a new resource with the provided data. In RESTful web services, the HTTP method PUT is typically used for both creating new data and updating existing data.

Example:

DELETE Method:
DELETE is used to remove a resource from the server. It is an idempotent method, meaning repeated DELETE requests will have the same effect as a single request.

Example:

HEAD Method:
The HEAD method is similar to GET, but it retrieves only the headers of a resource without the actual data. It is useful when you need to check the headers before downloading the entire resource.

Example:

OPTIONS Method:
The OPTIONS method is used to determine the communication options available for a given resource. It helps the client understand which HTTP methods and headers are supported.

Example:

PATCH Method:
PATCH is used to apply partial modifications to a resource. It is more efficient than PUT when updating only specific fields of a resource.

Example:

HTTP status codes are three-digit codes that indicate the outcome of an API request. They are included in the API’s response to the API client, and they include important information that helps the client know how to proceed.
What are the different types of HTTP status codes?
HTTP status codes are grouped into five classes, each beginning with a number that represents the type of response. The classes are:

1xx informational responses
These codes indicate that the server has received the request and is processing it. They are primarily used to manage communication between the client and server during the early stages of a request-response cycle. Some examples of this type of code are:

100 Continue: This status code indicates that the initial part of the request has been received and the server would like the client to send the rest of it.
101 Switching Protocols: This status code is used to inform the client that the server is changing the protocol that is being used in the connection.
102 Processing: This status code is an interim response that indicates the server is still processing the request.

2xx success responses
These codes indicate that the client’s request was successfully received, understood, and processed by the server. Some of the most common 200 responses are:

200 OK: This status code indicates that the request was successful, and the server returned the requested data.
201 Created: This status code means that the request was successful, and the server created a new resource.
204 No Content: This status code indicates that the request was successful, but the server did not return any data.

3xx redirection responses
These codes indicate that the client needs to take additional actions to fulfill the request. They are often used when the requested resource has moved to a different location. Some examples include:

301 Moved Permanently: This status code indicates that the requested resource has been permanently moved to a new URL. Clients should respond by updating their bookmarks and links to point to the new URL, and search engines should update their indexes with the new location.
303 See Other: This status code indicates that the response is available at a different URL, and the client should perform a GET request to that URL to retrieve the resource.

4xx client error responses
These codes indicate that there was an issue with the client’s request, such as a mistyped URL or invalid credentials. The most common 4xx responses include:

400 Bad Request: This status code indicates that the request was malformed or invalid.
401 Unauthorized: This status code lets the client know that it is not authorized to access the requested resource.
403 Forbidden: This status code communicates that the client is authenticated but not authorized to access the requested resource.
404 Not Found: This status code indicates that the requested resource was not found on the server.

5xx server error responses
These codes, which indicate that the server encountered an error while trying to fulfill the client’s request, include:

500 Internal Server Error: This generic error code indicates the server encountered an unexpected condition that prevented it from fulfilling the request.
502 Bad Gateway: This status code indicates that a server acting as a gateway or proxy received an invalid response from an upstream server.
503 Service Unavailable: This status code is returned when the server is temporarily unable to handle the request. It’s often seen during periods of increased traffic or when the server is undergoing maintenance.