Top 20 HTTP Interview Questions and Answers

We have Collected Top HTTP Interview Questions And Answers which will help beginners as well as experienced persons to understand the basic to advanced concepts. Mastering the questions presented in this blog would give you immense confidence to crack the interview in an easy way.

Most Frequently Asked HTTP Interview Questions

1. What is HTTP?

Ans:
Hypertext Transfer Protocol (HTTP) is a set of rules for transferring the data for the world wide web(www).

2. What is HTTP Session?

Ans:
An HTTP session is a series of network (request-response) transactions. An HTTP client sends a request and establishes a transmission control protocol connection(TCP) to the specific host. An HTTP server starts listening to the port and waits for the client request or message. Upon receiving the message or request, the server sends a status line to the client.

3. What is a request message?

Ans:
Request message means- An HTTP client sends a request to the server. The request message consists of the following:

  • Request line, such as GET /images/logo.png HTTP/1.1, which requests a resource

Called /images/logo.png from server

  • Headers, such as Accept-Language: en
  • An empty line
  • An optional message body

4. Explain different types of HTTP request methods?

Ans: 
The following are the different types of HTTP request methods:

  • GET
  • POST
  • PUT
  • HEAD
  • DELETE
  • OPTIONS

We are going to discuss the above methods one by one with an insight information:

GET:
The GET method is used to request the data from a particular resource. It is one of the most common HTTP methods. The query string (values/name pairs) is sent in the URL of a GET method. 
        

/test/demo_form.php?name1=value1&name2=value2

POST:
The POST method is used to send a message or data to a server to update/create a resource. The message or data is sent to the server with the POST is stored in the request body of the HTTP request. POST is also one of the most used HTTP methods. 

       POST /test/demo_form.php HTTP/1.1
       Host: w3schools.com
       name1=value1&name2=value2

PUT:
The PUT method is used to send the data or message to a server to create/update a resource. The difference between PUT and POST methods is PUT requests are idempotent i.e calling the same PUT request multiple times will give the same value. But if calling the same POST method repeatedly may create the same resource multiple times. 


HEAD:

The HEAD method is similar to the GET method, but without the response body. In other words, if the GET method returns a list of users, then HEAD method will make the same request but will not return the list of users.

DELETE:
The DELETE method deletes particular resource. 


OPTION:
The OPTION method describes the communication options for the end-users or target resources. 

PATCH:
This method is applied for the modifications.


5. Explain safe methods?

Ans:
Safe methods are HTTP methods, that does not change or alter the message or data of resources. Safe methods are also called as idempotent methods. For instance, using POST and GET methods on a resource URL, should never change or modify the original data of the resources.

6. Explain Idempotent Methods?

Ans:
An idempotent method is one of the HTTP methods that can be called many times with different outcomes or values. If the idempotent method is called once or multiple times, it gives the same result.

HTTP Interview Questions and Answers :

7. What is the status code?

Ans:
The status code is a 3-digit integer where the first digit defines the class of response and the last 2-digits do not have a specific categorization roles. Status codes are issued by a server in response to a client’s request to the server. For the first digit, five classes are defined: 

  • 1xx informational response – the request was received and continue the process.
  • 2xx successful – the request was successfully received, understood and accepted.
  • 3xx redirection – further action needs to be taken in order to complete the request.
  • 4xx client error – the request contains bad syntax or cannot be fulfilled.
  • 5xx server error – the server failed to fulfill an apparently valid request.
     

8. What is persistent connections?

Ans:
HTTP persistent connection is also called as HTTP connection reuse or keep-alive, it is the idea of using a single TCP connection to receive and send multiple HTTP response/requests from the same client and server. The connection is closed if it is not used for some configurable amount of time.

9. What is an HTTP session state?

Ans:
HTTP is a stateless protocol. A stateless protocol does not require the server to maintain the information or status about each user during the transaction of multiple requests.

10. What is a secure HTTP connection?

Ans:
To establish a secure HTTP connection, currently, there are two methods. 

  1. The HTTPs url scheme
  2. HTTP 1.1 upgrade header

11.  What is HTTPs Url scheme?

Ans:
The HTTP URL scheme is a part of the link that specifies the types of applications that you are opened in the browser.

12. From what HTTP messages are made?

Ans:
HTTP messages consist of header and body. The body contains instructions of header or it can remain empty. The header contains metadata, such that it encodes the information or data. The header also contains the HTTP methods.

13. What happens to the undeliverable datagrams?

Ans:
Undeliverable datagrams are discarded and an ICMP error message is sent to the source host.

14. What is cURL in HTTP?

Ans:
a cURL is a command-line tool that is available in all operating systems.

15. What are HTTP verbs?

Ans:
HTTP verbs tell the server what to do with the data that is identified by the URL. The data can contain additional information about the operation that needs to be performed.

16. What Is The Mean Of 500 Internal Server Error HTTP Response Codes?

Ans:
When all else conditions are failed; a general 500 internal server error is used to know that there is an unanticipated circumstance on the server-side.

17. What is meant by the representations in HTTP?

Ans:
The HTTP server and client exchange the information or the data about the resources that are identified by URLs. By representing the information about the resources, states how the resource should be used in the future.

18. What is mean by 200 OK HTTP response code?

Ans:
200 OK HTTP response code indicates that the request was successful.

19. What is mean by 201 created HTTP response code?

Ans:
201 created HTTP response code indicates that the request was successful and a resource was created. It is used to confirm the success of a POST or PUT request.

20. What is mean of 400 bad request HTTP response code?

Ans:
400 bad request HTTP response code indicates the request was malformed. This happens especially with the PUT and POST requests when the data or the information was not in the valid or correct format.

21. What is the mean of 404 not found HTTP response code?

Ans:
404 not found HTTP response code indicates that the required resource or information could not be found.

22 What is the mean of 401 unauthorized HTTP response code?

Ans:
The 401 unauthorized HTTP response code indicates that you need to perform the authentication before accessing the resources.

23 What is the mean of 405 Method Not Allowed HTTP response code?

Ans:
This response code indicates that it is not supported by the current resources.

24 What is the mean of 409 conflict HTTP response code?

Ans:
This response code indicates the conflicts.

25 Tell me to which OSI layer does IP belong?

Ans:
IP (Internet Protocol) belongs to the network layer in the OSI model.

26 What do you mean by IP is an unreliable protocol? 

Ans:
IP is an unreliable protocol because it does not guarantee the delivery of the datagram to the destination port.

27 Describe different roles of HTTP?

Ans:
In HTTP, there are two roles- client and server. The client always sends the message to the server, server reply to the conversation.

Conclusion:

With this, we have come to an end of HTTP interview questions and answers blog. I Hope these HTTP Interview Questions will help you in your interviews. In case you have attended any HTTP interview in the recent past, do paste those interview questions in the comments section and we’ll answer them. You can also comment below if you have any questions in your mind, which you might face in your interview.