1 00:00:01,520 --> 00:00:04,440 Hellooooo! 2 00:00:04,740 --> 00:00:07,950 That was a little bit excessive but I'm very very excited to start the course. 3 00:00:08,430 --> 00:00:12,959 So in this section we're going to be talking about browsing the web it's the first part in the How 4 00:00:12,960 --> 00:00:16,560 the Internet Works section, and some of you are thinking right now. 5 00:00:16,650 --> 00:00:18,070 Whoa, whoa, whoa Andrei, 6 00:00:18,270 --> 00:00:18,770 come on. 7 00:00:18,870 --> 00:00:20,159 I know how the Internet works. 8 00:00:20,160 --> 00:00:20,780 Let's get to the 9 00:00:20,781 --> 00:00:23,420 heavy, you know, technical stuff. 10 00:00:23,430 --> 00:00:28,459 But this is something that actually took me quite a few years to learn. 11 00:00:28,460 --> 00:00:34,419 And I see a lot of people just skimming the surface of this stuff without fully understanding how everything 12 00:00:34,420 --> 00:00:40,059 works together, without having those foundations it's actually very, very difficult to think about performance, 13 00:00:40,060 --> 00:00:42,659 optimizing your sites and so on and so on. 14 00:00:42,660 --> 00:00:45,809 So we're going to start off very, very basic and we're going to learn something 15 00:00:45,810 --> 00:00:52,840 that took me many years to to learn and once I figured this out everything clicked so just hang in there 16 00:00:52,960 --> 00:00:56,836 trust me, I promise you you'll learn something new in this section and we're going to be talking about 17 00:00:56,860 --> 00:00:58,160 browsing the web. 18 00:00:58,170 --> 00:01:05,910 We have over here a laptop and we have our browser let's say Google Chrome and we typically like 19 00:01:05,920 --> 00:01:11,419 to say, go to Google and we're going to visit Google so we type in Google.com 20 00:01:11,420 --> 00:01:14,190 Well what happens technically when we do that? 21 00:01:14,240 --> 00:01:18,900 When we enter Google.com we press enter on our keyboard. 22 00:01:18,940 --> 00:01:21,409 We ask a question who's this Google.com fellow? 23 00:01:21,410 --> 00:01:26,470 And that question gets asked all the way down to our ISP. 24 00:01:26,480 --> 00:01:30,899 ISP is Internet Service Provider and I put a dollar sign up here just so you know those are 25 00:01:30,900 --> 00:01:33,769 the people that you pay so you can have Internet. 26 00:01:33,770 --> 00:01:36,949 So if you're in the states that's Cogiko, Verizon. 27 00:01:36,950 --> 00:01:42,289 If you're in Canada that'll be Bell or Rogers or you know, depending on your country you have your big big 28 00:01:42,290 --> 00:01:48,710 companies that make a lot of money from Internet usage. So they get that request and they send that off 29 00:01:48,740 --> 00:01:54,390 to something called the DNS server so Domain Name Servers and we'll get into that later on in the course. 30 00:01:55,360 --> 00:01:56,520 So don't worry too much about it. 31 00:01:56,530 --> 00:02:02,280 But essentially it's a phone book - a phone book that has the list of all these URLs 32 00:02:02,370 --> 00:02:08,150 like Google.com and it has the addresses of them, so exactly like a phone book. 33 00:02:08,190 --> 00:02:12,890 They know where Google.com is so they say, "Hey you know, I don't know Mr. Google.com 34 00:02:12,920 --> 00:02:15,990 personally, but I do know his address. 35 00:02:16,010 --> 00:02:17,470 So you should go check him out." 36 00:02:17,520 --> 00:02:24,909 So they send off that request back through the ISP and the website or the web browser, Google Chrome 37 00:02:24,910 --> 00:02:32,040 in this case gets "172.217.7.23" alright, cool, but nothing is showing up yet. 38 00:02:32,050 --> 00:02:35,370 There's no there's no Google.com, I can't do any searches yet. 39 00:02:36,300 --> 00:02:39,980 OK we receive - it's what we call an IP address. 40 00:02:40,050 --> 00:02:46,560 So think of this as something that every single computer has one, anything that's connected to the Internet 41 00:02:46,590 --> 00:02:52,289 has its own address so the laptop that I'm working on right now an IP address, your laptop or computer 42 00:02:52,290 --> 00:02:53,440 has an IP address. 43 00:02:53,910 --> 00:03:00,479 So this IP address allows the Internet to work essentially, it knows our location our address. 44 00:03:00,480 --> 00:03:06,370 So what we do now with Google.com we know this IP address - the browser sends off another request 45 00:03:06,390 --> 00:03:12,180 to the Google servers and it knows where the Google servers are because, well because we have this address 46 00:03:12,270 --> 00:03:18,810 so we go seek it out and you can think of servers as computers essentially. 47 00:03:19,080 --> 00:03:22,690 My laptop could be a server your computer could be a server. 48 00:03:22,700 --> 00:03:29,930 Servers are essentially computers that are sometimes in basements or in huge server farms 49 00:03:30,000 --> 00:03:37,620 and they have a piece of software running that just like at a restaurant where a server brings you food. 50 00:03:37,680 --> 00:03:41,439 It knows how to send you files when you request for them. 51 00:03:41,440 --> 00:03:47,409 So we send this off and the Google servers say oh yeah no problem, 52 00:03:47,410 --> 00:03:52,719 let me give you my HTML CSS and Javascript and we'll get into what those are 53 00:03:52,720 --> 00:03:59,179 later on in the course, but think of them as just text files. They are text files that Google is going to send 54 00:03:59,180 --> 00:04:02,400 to the browser so we can have Google working. 55 00:04:02,410 --> 00:04:07,509 So let me just minimize this and show you what it's doing. 56 00:04:07,510 --> 00:04:14,160 So we're copying these files and Google server's saying yeah no problem thanks for asking for Google. 57 00:04:14,170 --> 00:04:15,170 Here it is. 58 00:04:15,340 --> 00:04:18,579 And the web browser receives the HTML, CSS, 59 00:04:18,940 --> 00:04:20,108 and javascript. 60 00:04:20,110 --> 00:04:26,670 So if we go to the next section boom we have google.com and everything's working. 61 00:04:26,740 --> 00:04:33,580 Now that sounded like a whole bunch of stuff that happened in between and when we're on the internet 62 00:04:33,610 --> 00:04:39,639 everything is quite fast but yet underneath the hood all of that is happening and it's crazy to think 63 00:04:39,640 --> 00:04:42,759 how fast everything works. 64 00:04:42,760 --> 00:04:43,900 Don't take my word for it. 65 00:04:43,960 --> 00:04:48,910 Let's just check this process that I'm not just making stuff up for you. 66 00:04:50,180 --> 00:04:56,009 If what we learned was correct, technically we can skip this process right. 67 00:04:56,010 --> 00:05:04,599 I mean if we know the address of Google can we just, you know, go into this directly and just instead 68 00:05:04,600 --> 00:05:10,749 of putting Google.com, just put in this in our search bar and it automatically goes to the Google servers. 69 00:05:10,790 --> 00:05:12,310 Well let's try it out. 70 00:05:12,320 --> 00:05:14,699 Let's let's open up Google here. 71 00:05:14,700 --> 00:05:16,360 And ooh, what a pretty picture. 72 00:05:16,370 --> 00:05:16,730 All right. 73 00:05:16,850 --> 00:05:25,489 So we go to Google.com, nothing crazy here and that's great but, what if instead of that I put in 74 00:05:25,490 --> 00:05:31,030 the IP address so 172, there's no way I could remember this address, so I've done this before 75 00:05:31,040 --> 00:05:35,239 and I press Enter look at that, Google.com. 76 00:05:35,320 --> 00:05:39,100 So as you can see, I'm not lying. 77 00:05:39,290 --> 00:05:44,999 It's what's happening. The IP address gets sent to the Google servers - Google servers sends us a few 78 00:05:45,000 --> 00:05:51,029 files so that we can finally load Google.com. In the next section we're going to do something fun. 79 00:05:51,030 --> 00:05:56,735 We're going to break a bit of Google and - and toy around with the webite again to show you how cool 80 00:05:56,736 --> 00:05:58,270 all of this technology is. 81 00:05:58,340 --> 00:05:59,900 See you in the next one! Bye-Bye!