The Back-End and the Request/Response Cycle - Full Stack Web Development Basics
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The Back-End and the Request/Response Cycle

The Back-End and the Request/Response Cycle

The back-end of a web application ensures functionality, dynamic content, and data handling, while its relationship with the front-end is fundamental to user interaction. Key processes include understanding the request/response cycle, HTTP methods, and how servers and databases interact. Real-life analogies and practical coding examples, especially with Node.js, illustrate these concepts effectively.

40 sections

Sections

Navigate through the learning materials and practice exercises.

  1. 3
    The Back-End And The Request/response Cycle

    The back-end of web applications processes user requests and manages data,...

  2. 3.1
    Introduction

    This section introduces the back-end of web applications, explaining its...

  3. 3.2
    What Is The Back-End?

    The back-end is the behind-the-scenes powerhouse of web applications,...

  4. 3.2.1

    The back-end of a web application is essential for processing user requests...

  5. 3.2.2
    Why Is The Back-End Important?

    The back-end of a web application is essential for creating dynamic and...

  6. 3.2.3
    Components Of The Back-End

    The back-end of a web application consists of servers, databases, and...

  7. 3.2.3.1

    The server is a crucial component of the back-end, responsible for...

  8. 3.2.3.2

    Databases are vital components of the back-end system that securely store,...

  9. 3.2.3.3
    Server-Side Code

    Server-side code is critical for processing requests in web applications,...

  10. 3.3
    The Server – The Heart Of The Back-End

    This section explains the role and functionality of servers in the back-end...

  11. 3.3.1
    What Is A Server?

    A server is a vital component of the back-end, responsible for processing...

  12. 3.3.2
    How Does A Server Work?

    Servers are essential components of the back-end in web applications,...

  13. 3.3.3
    Diagram Explained In Text

    This section elaborates on the request/response cycle, detailing how user...

  14. 3.4
    The Database – Where Information Lives

    The database is a crucial component of the back-end, responsible for...

  15. 3.4.1
    Example – User Database
  16. 3.4.2
    Types Of Databases

    This section covers the different types of databases used in web...

  17. 3.5
    Server-Side Code – Instructions For The Server

    This section covers the role of server-side code in web applications,...

  18. 3.5.1
    Example Scenario – Handling Login

    This section explains the process of handling user login requests within a...

  19. 3.6
    The Request/response Cycle – How It All Happens

    The section covers the request/response cycle, which is fundamental to how...

  20. 3.6.1

    The back-end of web applications powers functionality behind the scenes,...

  21. 3.6.2
    Step 1 – The Request

    The request is the initial step in the request/response cycle, where the...

  22. 3.6.3
    Step 2 – Server Processing

    In this section, we explore how a server processes incoming requests and...

  23. 3.6.4
    Step 3 – The Response

    This section explains the response phase of the request/response cycle,...

  24. 3.6.5
    Real-Life Scenario – Contact Form Submission

    This section describes the back-end processes involved when a user submits a...

  25. 3.7
    Http Methods – Actions You Can Perform

    This section outlines the various HTTP methods that define the actions users...

  26. 3.7.1
    Get – Retrieve Data

    The GET method is an essential HTTP request used to retrieve data without...

  27. 3.7.2
    Post – Send Data

    The POST method in HTTP is used to send data to a server, commonly for tasks...

  28. 3.7.3
    Put – Update Data

    The PUT method in HTTP is used to modify existing data on a server, allowing...

  29. 3.7.4
    Delete – Remove Data

    This section describes the DELETE HTTP method, highlighting its role in...

  30. 3.8
    Http Status Codes – Understanding The Server’s Response

    HTTP status codes inform clients about the outcome of their server requests.

  31. 3.8.1
    Common Status Codes

    This section focuses on HTTP status codes used to communicate the outcome of...

  32. 3.8.2
    Example – Handling Errors
  33. 3.9
    Example – Complete Request/response Cycle Using Node.js
  34. 3.9.1
    How It Works

    The section 'How it Works' explains the back-end processes of web...

  35. 3.9.2

    This section explores the mechanics of the request/response cycle in web...

  36. 3.10
    Real-World Example – Form Submission

    This section illustrates the practicalities of how data is submitted through...

  37. 3.11
    Security In The Request/response Cycle

    This section highlights the importance of security measures within the...

  38. 3.11.1
    Why Security Is Important

    This section emphasizes the importance of security within the back-end of...

  39. 3.11.2
    Example – Avoiding Sql Injection
  40. 3.12

    This section summarizes the key concepts surrounding the back-end of web...

What we have learnt

  • The back-end powers the functionality of a web application.
  • A server listens for requests, processes them, and sends responses.
  • A database stores and retrieves information securely.
  • Server-side code handles logic, validation, and operations.
  • The request/response cycle connects the front-end and back-end.
  • HTTP methods like GET, POST, PUT, DELETE define actions to perform.
  • HTTP status codes explain how requests are handled.
  • Security best practices ensure data integrity and user safety.

Key Concepts

-- BackEnd
Refers to everything that happens behind the scenes of a web application, responsible for data handling, storage, processing, and retrieval.
-- Server
A machine or program that listens for requests from clients, processes those requests, and sends appropriate responses.
-- Database
A system that securely stores and manages data used by applications.
-- Request/Response Cycle
The process by which front-end and back-end communicate, involving sending requests and receiving responses.
-- HTTP Methods
Actions defined by the HTTP protocol, such as GET, POST, PUT, and DELETE, that dictate how data should be sent and manipulated.

Additional Learning Materials

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