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What is the Back-end?
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  1. 1
    In this lesson, we’ll explain what makes up the back-end of a web application or website. The back-end can feel very abstract, but it becomes clearer when we explain it in terms of the front-end! T…
  2. 2
    We talked about how the front-end consists of the information sent to a client so that a user can see and interact with a website, but where does the information come from? The answer is a _web ser…
  3. 3
    When a user navigates to google.com, their request specifies the URL but not the filename for today’s Google Doodle . The web application’s back-end will need to hold the logic for deciding which …
  4. 4
    You’ve probably heard that data is a big deal. By some measures, 90% of the world’s data has been generated in just the past two years! From a stored credit card number on an e-commerce site to the…
  5. 5
    When a user navigates to a specific item for sale on an e-commerce site, the price listed for that item is stored in a database, and when they purchase it, the database will need to be updated with…
  6. 6
    Two other concepts we’ll want our server-side logic to handle are authentication and authorization. Authentication is the process of validating the identity of a user. One technique for aut…
  7. 7
    Unlike the front-end, which must be built using HTML, CSS, and JavaScript, there’s a lot of flexibility in which technologies can be used in order to create the back-end of a web application. Devel…
  8. 8
    In order to deliver the front-end of a website or web application to a user, a lot needs to happen behind the scenes on the back-end! Understanding what makes up the back-end can be overwhelming be…
  1. 1
    For a long time, the browser was the only place JavaScript code could be executed. Web developers had to use a different programming language on the front-end than the back-end. It also meant that,…
  2. 2
    REPL is an abbreviation for read–eval–print loop. It’s a program that loops, or repeatedly cycles, through three different states: a read state where the program reads…
  3. 3
    Node was designed with server-side web development in mind and has a lot of thoughtful functionality towards that end. At its most simple, however, it provides the ability to run JavaScript program…
  4. 4
    In computer science, a process is the instance of a computer program that is being executed. You can open Task Manager if you’re on a Windows machine or Activity Monitor from a Mac to see informa…
  5. 5
    Modularity is a software design technique where one program has distinct parts each providing a single piece of the overall functionality. These separate modules come together to build a cohesi…
  6. 6
    In addition to local modules and core modules, we can take advantage of third-party modules. Using libraries created by other developers is an essential aspect of production; we don’t have to reinv…
  7. 7
    Node is often described as having event-driven architecture. Let’s explore what that means. In traditional imperative programming, we give the computer a series of instructions to execute in a pr…
  8. 8
    In server-side development, we often perform time-consuming tasks such as reading files or querying a database. Instead of halting the execution of our code to await these operations or using multi…
  9. 9
    If you’ve worked with JavaScript before, you’re likely familiar with the concept of input/output even if you haven’t heard it called that. At its most abstract, output is any data or feedback tha…
  10. 10
    The Node environment has all the standard JavaScript errors such as EvalError, SyntaxError, RangeError, ReferenceError, TypeError, and URIError as well as the JavaScript Error class for creating ne…
  11. 11
    All of the data on a computer is organized and accessed through a filesystem. When running JavaScript code on a browser, it’s important for a script to have only limited access to a user’s filesy…
  12. 12
    In the previous exercise, we practiced reading the contents of entire files into our JavaScript programs. In more realistic scenarios, data isn’t processed all at once but rather sequentially, piec…
  13. 13
    In the previous exercise, we were reading data from a stream, but we can also write to streams! We can create a writeable stream to a file using the fs.createWriteStream() method: const fs = requi…
  14. 14
    Node was designed with back end development needs as a top priority. One of these needs is the ability to create web servers, computer processes that listen for requests from clients and return res…
  15. 15
    Awesome work! You’ve learned a lot about Node.js including: + Node.js is a JavaScript runtime, an environment that allows us to execute our JavaScript code by converting it into something a compu…

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