All language subtitles for 1. Backend Web Development Explained

All right.
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So now that we've looked at a lot of the technologies that are used in front end web development, and we've
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designed and developed web sites using HTML, CSS, Javascript, Bootstrap, jQuery, in order to become a
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full stack web developer, we now have to learn about the back end.
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Now what exactly is a full stack developer?
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Because this is a term that's brandished about a lot and especially in the context of development jobs.
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So, according to Linked In, these are the hottest jobs for 2018, and squarely on that list is a full stack
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developer.
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So what exactly is a full stack developer?
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Well, a full stack basically is just front end development plus back end development.
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And once you're familiar with both, then it's this flexibility of working with the front and back end
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that makes you so much more desirable as a developer.
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Up till now we've only been interacting with front end technologies. We’ve learnt about HTML, CSS
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and Javascript, as well as jQuery and Bootstrap, which all enable us to design our web site and also
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allow for user interaction on the client side, in the browser for example.
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But now we're going to look at the back end. We’re going to learn about Node.js and other technologies
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that enable us to interact with databases or have business logic on a server and a whole lot more.
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Now what exactly is the back end anyways? For some of you out there who are a bit more immature like myself,
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don’t worry, it's not something that's rude.
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Instead it consists of things such as a server which will serve up your files your HTML, your
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CSS and your Javascript, a database which can store your user data such as their log ins and passwords,
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as well as your applications.
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So this is where you create your business logic,
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you determine how your web applications work,
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for example things such as calculating flight prices, or making payments, that sort of stuff.
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So let's look at a real life example. Let’s take a look at the Eventbrite
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web application.
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And it's a web application because it doesn't just display information,
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it also has functionality on the back end that enables it to do something concrete, such as find events
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or allow you to book events.
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So let's say we've gone to Eventbrite and we look at all the events that are happening today, and I
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find something that is the Hogarth beer and music festival.
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Well, that sounds right up my alley.
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So let's go ahead and register and book a ticket.
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So here I enter my name and I buy a ticket.
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Well now, that information that consists of my name, how many tickets I bought, and my registration details
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such as my e-mail, gets saved on the web site's databases.
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And for simplicity's sake you can just imagine these databases as these giant Excel spreadsheets living
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somewhere. And all of my data that I enter gets saved onto these spreadsheets.
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And that means that when I come back at a later date, I'm able to log back on to Eventbrite, and it
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will be able to retrieve from its database
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all of the data that is associated with my account.
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So, for example, it could retrieve my ticket to the Hogarth beer and music festival. Now a really great
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analogy for a full stack web application, it's kind of like a restaurant.
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So there is a front of house.
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This is the main restaurant where your clients will sit down and have dinner.
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But then there's also the kitchen, right, which is where the cooking is mostly happening.
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And finally there's also the larder, which is where you store all of your ingredients and everything
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you need to make the food.
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In this analogy our front of house restaurant is basically the client side.
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This is what the user sees in the browser.
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They're able to interact with the web site using Javascript and they're able to see the information
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that's being displayed using HTML and CSS.
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Now, a little bit further back on the back end, we've got the kitchen, and this is analogous to our server.
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This is basically the place where all of our dishes get served from.
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So, when a restaurant goer ask for a Philly steak, then that order gets sent to the server, and the server
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should send back what it is that the client wanted, which is the actual steak.
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And finally the larder where all the ingredients are stored is of course the database.
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This is where all of our user data, our event data, our ticket data,
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all of the data that makes our web site work is stored.
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So this is where the divide between the front end and the back end happens. It’s between the front of
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the house and the restaurant, and the kitchens and larder.
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Now, just as with restaurants, you don't actually have to create everything in the kitchens,
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right?
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You could have a restaurant where you make all of the dishes in front of the client, and you just do
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it on their table. You bring all of the ingredients there and you make it right there for them.
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Now the downsides in this case is that, firstly, your secret recipe that's been passed down over generations
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from your great grandma to your grandma to your mother to your self,
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well that's kind of exposed, right?
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Anybody would be able to see what it is that you're doing,
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and they would be able to replicate it.
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And this is the same for the business logic of your web site.
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If you had something that you wanted to keep secret such as your API keys or how you implement your
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particular application, then you don't want that to be visible every time somebody loads up a web site, right?
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And the other problem is that it can be really really time consuming to make the dish in front
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of the client in the restaurant, because you would have to bring all of the ingredients,
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you would have to make it one by one in small batches, and in web sites that translates to a long loading
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time.
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So if you are transporting a lot of code over to the browser where it has to be executed on the browser,
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that usually takes a lot longer than if it was done on the back end.
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So the alternative is we take our ingredients from our database, so our server interacts with the database,
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then we execute some code on our server and we create the application or the dish,
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in this case, which then gets served to the client side.
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So that means we don't have to transport any of the ingredients,
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we don't have to transport a lot of code, which will vastly speed up your web site, and also keep your
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business logic hidden. On the back
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end there's a lot of technologies that are commonly used for this purpose, and these include PHP, Ruby,
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Java, Node.js, amongst many many others.
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Now, in addition, there are frameworks, such as CakePHP or Ruby on Rails or Spring, Express, and these are
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things that will speed up development using the particular back end technology you chose.
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So a common one you would have heard is maybe Ruby and Ruby on Rails, and the main job of these frameworks
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is to simply reduce the amount of repetitive stuff that a developer has to do,
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and just like how you don't want to write the email boilerplate code out every single time you create
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an additional page,
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then in the same way a lot of these frameworks such as Ruby on Rails or Express, they make a developer's
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life much much easier by cutting down some of the grunt work and saving you a lot of time. In the coming
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lessons we’re going to be delving deep into a lot of this kind of stuff,
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and we're going to be learning about Node.js as well as the most common framework that's used with it,
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which is Express. And the best part of all is that we don't have to learn a brand new programming language
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to do it, because Node.js runs on Javascript.
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And this is why Node.js is one of the most popular back end languages currently, because it runs on
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Javascript.
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So for all of that and more on Node.js, I'll see you on the next lesson.