20 HTTP Protocol Interview Questions and Answers

HTTP is the protocol that governs communication on the World Wide Web. When applying for a position in web development or coding, you may be asked questions about HTTP during your job interview. Reviewing common HTTP questions ahead of time can help you prepare your responses and feel confident on the day of your interview. In this article, we review some questions you may have during your job interview.

HTTP Protocol Interview Questions and Answers

Here are 20 commonly asked HTTP Protocol interview questions and answers to prepare you for your interview:

1. What is HTTP?

HTTP is the protocol that governs communication between web servers and clients. It is the foundation of the World Wide Web.

2. How does the HTTP protocol work?

The HTTP protocol is a request-response protocol. A client, typically a web browser, sends a request to a server, and the server responds with the requested resource. The HTTP protocol defines a set of methods, or verbs, that the client can use to request a resource from the server. The most common methods are GET, which requests a resource from the server, and POST, which submits data to the server.

3. What does REST stand for and what are its associated principles?

REST stands for Representational State Transfer. It is an architectural style for designing networked applications. The main principles associated with REST are statelessness, uniform interface, cacheability, and layering.

4. Can you explain how to make an HTTP request in code?

To make an HTTP request, you will need to use a library or framework that supports making HTTP requests. For example, in the Python standard library, there is a module called “urllib” that contains functions for making HTTP requests.

Once you have imported the appropriate library or module, you can use its functions to make an HTTP request. For example, in Python, you would use the “urllib.request” function to make an HTTP request. This function takes as arguments the URL of the request, the data to be sent (if any), and headers (if any).

5. Can you describe some of the differences between HTTP 1.1 and HTTP 2.0?

HTTP 1.1 is a text-based protocol, while HTTP 2.0 is binary-based. HTTP 1.1 also uses a separate connection for each request, while HTTP 2.0 can multiplex requests over a single connection. Finally, HTTP 2.0 uses header compression to reduce overhead, while HTTP 1.1 does not.

6. Does HTTP support stateful operations? If not, why not?

No, HTTP does not support stateful operations. The main reason for this is that stateless operations are much simpler to implement, which makes them more scalable. Stateful operations would require the server to keep track of a lot of information about each client, which would quickly become unmanageable.

7. Is it possible to use HTTP over UDP instead of TCP? If yes, then how?

Yes, it is possible to use HTTP over UDP instead of TCP. This can be done by using a protocol known as HTTP-tunneling. HTTP-tunneling allows HTTP traffic to be sent over UDP by encapsulating the HTTP traffic in UDP packets.

8. What do you understand by HTTP headers?

HTTP headers are the key-value pairs that are sent along with an HTTP request or response. They provide information about the request or response, such as the content type, the date and time, the server, and so on.

9. What’s the difference between authorization and authentication?

Authentication is the process of verifying that a user is who they say they are, while authorization is the process of verifying that a user has the permissions necessary to access a particular resource. In other words, authentication is about verifying identity, while authorization is about verifying permissions.

10. Can you give me some examples of common HTTP response codes?

Some common HTTP response codes include:

200 OK – The request was successful

400 Bad Request – The request could not be understood by the server

401 Unauthorized – The request requires authentication

403 Forbidden – The server is refusing to fulfill the request

404 Not Found – The requested resource could not be found

500 Internal Server Error – The server encountered an error while processing the request

11. What are some advantages of using HTTPS compared with HTTP?

HTTPS is the more secure version of the HTTP protocol, and thus has a few advantages over its predecessor. For one, HTTPS encrypts all communication between the client and server, making it much more difficult for third parties to intercept and read data. Additionally, HTTPS also authenticates the server, meaning that clients can be sure that they are communicating with the intended party and not a imposter.

12. What’s the difference between a GET and POST request?

A GET request is used when you are trying to retrieve data from a server. A POST request is used when you are trying to send data to a server.

13. What is your understanding of HATEOAS?

HATEOAS is an acronym for Hypermedia As The Engine Of Application State. It is a constraint of the REST application architecture that keeps the client stateless by allowing all information needed for application state to be contained within hypermedia links. This means that instead of the client having to keep track of application state, the application state is embedded within the links themselves.

14. What do you understand by cookies?

Cookies are small pieces of data that are sent from a website to a user’s web browser. They are used to store information about the user’s interactions with the website, such as login information, preferences, and shopping cart contents.

15. Are there any other ways besides cookies to maintain client-side session data?

There are a few other ways to maintain client-side session data, but cookies are by far the most common. One alternative is to use HTML5 local storage, which can be used to store data on the client-side that persists even after the browser is closed. Another option is to use URL parameters, which can be used to pass data from one page to another.

16. Why do we need methods like PUT, DELETE, HEAD, TRACE, OPTIONS? Aren’t GET and POST enough?

The main reason for having multiple methods is to allow for different types of operations to be performed on a resource. GET is used for retrieving a resource, while POST is used for creating or updating a resource. PUT is used for replacing a resource, DELETE is used for deleting a resource, and HEAD is used for retrieving metadata about a resource. TRACE and OPTIONS are used for debugging and troubleshooting purposes.

17. What’s the importance of CSRF tokens?

CSRF tokens are important because they help to prevent cross-site request forgery attacks. These attacks can occur when a malicious user tricks a victim into submitting a request to a website that they are logged into. This can allow the attacker to perform actions on the website on behalf of the victim. CSRF tokens help to prevent these attacks by ensuring that only requests that originate from the same site as the user are processed.

18. Can you give me some examples of real-world applications that use the HTTP protocol?

The HTTP protocol is used by web browsers to request web pages from web servers. It is also used by email clients to retrieve email from email servers.

19. What are some techniques used to improve web security when using HTTP?

Some techniques used to improve web security when using HTTP include using SSL/TLS to encrypt communication, using digital signatures to verify the identity of the sender, and using firewalls to block unauthorized access.

20. What do you know about Cross-Site Scripting (XSS) attacks?

Cross-Site Scripting (XSS) attacks are a type of injection attack where malicious scripts are injected into webpages. These scripts can then be executed by unsuspecting users who visit the page, resulting in the theft of sensitive information or the execution of unwanted actions. XSS attacks can be prevented by proper input validation and output encoding.