Why use Node.js?

You may be asking, okay so I can write JavaScript on the server side, but 0:00 what's the big deal? 0:03 Why shouldn't I use other languages that are all ready being used on 0:04 the server side? 0:07 Here's an analogy to that will help illustrate why you'd want to use Node.js. 0:09 Imagine I have an assistant that I gave a stack of invoices to. 0:13 I asked them to send them out on my behalf. 0:17 The assistant sends the first invoice out and waits for the check for payment. 0:20 Once they receive the payment, they deposit it in the bank and 0:24 send out the next invoice. 0:27 Now this isn't good for me, I'm not getting paid as quickly as I could. 0:29 This is blocking me from receiving my payments, 0:33 blocking my business from growing, and blocking me from getting stuff done. 0:36 I've got two options, getting more assistants who will do the same thing or 0:41 get a new more efficient one. 0:45 The new more efficient assistant would send out all invoices and 0:47 process each payment as soon as it comes in. 0:51 I know some of my customers pay quicker than others, so I wouldn't want to wait to 0:54 deposit the payments in the same order I send out the invoices. 0:58 I want to deposit them as soon as I receive them. 1:03 This assistant knows that. 1:05 Not only is this assistant saving me a lot of resources by not having to employ 1:07 extra inefficient assistance. 1:12 But while they're waiting for payments from my clients, they're free to do 1:15 other things to assist me, like sending a thank you note when a payment is received. 1:18 You can say that this assistant is non-blocking, since they don't hinder me, 1:24 and improves my relationships with my existing customers. 1:28 Most languages and frameworks work like the first assistant, 1:32 handling one set of tasks from beginning to end 1:35 before repeating the process again doing the same set of steps for another task. 1:38 This sort of behavior manifests itself most noticeably 1:44 when you're doing a couple of things in a single web request, 1:47 like querying a database and uploading files to be saved to disk. 1:50 Imagine having a popular social network that required a profile image on sign up. 1:54 Imagine how frustrated your users would be if they had to wait for 1:59 all of the user images to be uploaded first. 2:03 It would be super frustrating, and I don't think you'd be popular for that long. 2:06 Languages that queue up requests, and process them one at a time like this 2:09 are known as blocking languages, since it blocks the handling of other requests. 2:15 Often developers scale these types of applications by running more than 2:20 one instance of their web applications. 2:24 These instances are known as workers. 2:26 However, Node.js works like the second, more efficient system, doing what it can 2:29 do now, responding to requests while it waits for other tasks to finish. 2:34 This often means when certain types of applications are ported to Node.js, you 2:39 don't necessarily require as much system resources to perform the same tasks. 2:43 Sometimes one Node.js worker can be even more responsive than the other languages. 2:49 Node.js is non-blocking and that's why you'd want to build JavaScript 2:55 applications on the Node.js platform over other languages and platforms. 2:58 It's fast and efficient. 3:03 It doesn't take up as many computer resources by the computers processing 3:04 power or memory. 3:09