1 00:00:00,570 --> 00:00:01,650 In this lesson, 2 00:00:01,650 --> 00:00:04,560 we're going to explore the Graphical User Interface 3 00:00:04,560 --> 00:00:06,960 and the major Linux GUI components. 4 00:00:06,960 --> 00:00:09,480 In many instances, people are more comfortable 5 00:00:09,480 --> 00:00:11,280 working in a visual environment 6 00:00:11,280 --> 00:00:14,790 than inside the Command Line Interface, or CLI. 7 00:00:14,790 --> 00:00:17,400 For this reason, it's really important for you to learn 8 00:00:17,400 --> 00:00:20,520 about the common window manager and desktop environments 9 00:00:20,520 --> 00:00:22,950 that you can use within Linux. 10 00:00:22,950 --> 00:00:25,620 Now, a GUI, or Graphical User Interface, 11 00:00:25,620 --> 00:00:28,890 enables users to interact with a system or application 12 00:00:28,890 --> 00:00:30,990 through various visual design elements 13 00:00:30,990 --> 00:00:32,640 rather than using pure text 14 00:00:32,640 --> 00:00:36,270 as in a command line interface, or CLI. 15 00:00:36,270 --> 00:00:39,990 In Linux, users can select icons that represent files, 16 00:00:39,990 --> 00:00:43,740 folders or programs to open them and modify them. 17 00:00:43,740 --> 00:00:45,870 They can configure settings through menus. 18 00:00:45,870 --> 00:00:47,490 They can interact with applications 19 00:00:47,490 --> 00:00:48,900 through a windowed interface 20 00:00:48,900 --> 00:00:51,570 and they can work from a desktop environment. 21 00:00:51,570 --> 00:00:54,030 A Display Server is the component of a GUI 22 00:00:54,030 --> 00:00:56,670 that constructs and manages the windowing system 23 00:00:56,670 --> 00:01:00,060 and other visual elements that can be drawn on the screen. 24 00:01:00,060 --> 00:01:02,880 Display Servers will accept client input requests 25 00:01:02,880 --> 00:01:04,260 and send them to the appropriate 26 00:01:04,260 --> 00:01:06,330 kernel modules for processing. 27 00:01:06,330 --> 00:01:09,900 Likewise, they also manage the process of receiving requests 28 00:01:09,900 --> 00:01:14,010 from an application and display that output to the client. 29 00:01:14,010 --> 00:01:16,140 while the kernel is the heart of Linux, 30 00:01:16,140 --> 00:01:17,700 the face of the operating system 31 00:01:17,700 --> 00:01:19,620 is really the graphical environment 32 00:01:19,620 --> 00:01:24,120 that's provided by the X Window System, also known as X. 33 00:01:24,120 --> 00:01:28,290 The X Window System can also be known as X or X11, 34 00:01:28,290 --> 00:01:29,970 and it is platform independent, 35 00:01:29,970 --> 00:01:32,970 and it works as a display server and windowing system 36 00:01:32,970 --> 00:01:33,990 that was originally developed 37 00:01:33,990 --> 00:01:36,420 by the Massachusetts Institute of Technology, 38 00:01:36,420 --> 00:01:40,200 or MIT, all the way back in 1984. 39 00:01:40,200 --> 00:01:42,570 Like all display servers, the X server 40 00:01:42,570 --> 00:01:45,570 coordinates client input and application output 41 00:01:45,570 --> 00:01:48,450 to determine how to draw elements on the screen. 42 00:01:48,450 --> 00:01:52,320 The X server also communicates with a separate compositor. 43 00:01:52,320 --> 00:01:54,900 The compositor is going to read a memory buffer 44 00:01:54,900 --> 00:01:57,060 that each application is going to write to 45 00:01:57,060 --> 00:02:00,150 and then it's going to use that information from the buffer 46 00:02:00,150 --> 00:02:02,520 to combine each individual application window 47 00:02:02,520 --> 00:02:03,840 onto the screen. 48 00:02:03,840 --> 00:02:07,230 That way, multiple windows can appear at once. 49 00:02:07,230 --> 00:02:10,020 This is the free and open source reference implementation 50 00:02:10,020 --> 00:02:12,390 of the X Window System for Linux, 51 00:02:12,390 --> 00:02:15,000 and other units like operating systems. 52 00:02:15,000 --> 00:02:17,370 Now, Wayland is both a display server 53 00:02:17,370 --> 00:02:19,530 and its reference implementation in a unit 54 00:02:19,530 --> 00:02:22,140 like operating system that is meant to approve upon 55 00:02:22,140 --> 00:02:24,720 and replace the X Window System. 56 00:02:24,720 --> 00:02:27,450 The primary difference between Wayland and X 57 00:02:27,450 --> 00:02:30,540 is that in Wayland, the compositor is the server 58 00:02:30,540 --> 00:02:32,550 rather than a separate component. 59 00:02:32,550 --> 00:02:35,100 This enables clients to exchange events directly 60 00:02:35,100 --> 00:02:37,560 with the compositor, cutting out the X server 61 00:02:37,560 --> 00:02:38,940 as a middleman. 62 00:02:38,940 --> 00:02:42,120 Although Wayland improves upon X in almost every way, 63 00:02:42,120 --> 00:02:44,520 there are still some issues with Wayland. 64 00:02:44,520 --> 00:02:46,980 For example, Canonical made Wayland 65 00:02:46,980 --> 00:02:50,670 the default display server for Ubuntu 17.10 66 00:02:50,670 --> 00:02:53,040 back in October of 2017. 67 00:02:53,040 --> 00:02:57,750 But in April, 2018 for the release of Ubuntu 18.04, 68 00:02:57,750 --> 00:02:59,670 Canonical announce that it switched back 69 00:02:59,670 --> 00:03:03,420 to the x.org server for three primary reasons. 70 00:03:03,420 --> 00:03:06,450 First, screen sharing software tends to work better 71 00:03:06,450 --> 00:03:09,540 under x.org servers than it did Wayland. 72 00:03:09,540 --> 00:03:12,840 Second, remote desktop software tended to work better 73 00:03:12,840 --> 00:03:14,970 under X than it did Wayland. 74 00:03:14,970 --> 00:03:18,660 And lastly, it was easier to recover from crashes under X 75 00:03:18,660 --> 00:03:20,490 than it was under Wayland. 76 00:03:20,490 --> 00:03:23,160 For this reason, Ubuntu migrate back to X 77 00:03:23,160 --> 00:03:26,610 in version 1804 and abandoned Wayland. 78 00:03:26,610 --> 00:03:30,000 Now a desktop environment includes a window manager, 79 00:03:30,000 --> 00:03:32,250 and this desktop environment will control the look 80 00:03:32,250 --> 00:03:35,490 and feel of the GUI for the entire operating system. 81 00:03:35,490 --> 00:03:37,770 And it provides a common Graphical Interface 82 00:03:37,770 --> 00:03:40,830 for applications that are running inside the environment. 83 00:03:40,830 --> 00:03:43,650 The primary structural element of the desktop metaphor 84 00:03:43,650 --> 00:03:45,480 is the application window. 85 00:03:45,480 --> 00:03:47,640 And within each window, there can exist 86 00:03:47,640 --> 00:03:50,190 various graphical elements like buttons, 87 00:03:50,190 --> 00:03:53,790 icons, menus, toolbars, and much more. 88 00:03:53,790 --> 00:03:57,240 Desktop environments also provide a graphical login screen 89 00:03:57,240 --> 00:04:00,810 and can be customized to run every time the system boots up. 90 00:04:00,810 --> 00:04:03,720 In most cases, the desktop environment will come packaged 91 00:04:03,720 --> 00:04:06,480 with a variety of different GUI applications. 92 00:04:06,480 --> 00:04:09,120 Things like file browsers, web browsers, 93 00:04:09,120 --> 00:04:11,430 texts editors and more. 94 00:04:11,430 --> 00:04:14,850 One exciting aspect of Linux, unlike Windows and Mac, 95 00:04:14,850 --> 00:04:17,966 is that it supports numerous different desktop environments. 96 00:04:17,966 --> 00:04:20,010 And this enables desktop users 97 00:04:20,010 --> 00:04:22,200 to actually choose the appropriate and most suitable 98 00:04:22,200 --> 00:04:25,320 desktop environment to best work with their needs. 99 00:04:25,320 --> 00:04:27,390 Now, there are many different desktop environments 100 00:04:27,390 --> 00:04:28,920 that are available for Linux 101 00:04:28,920 --> 00:04:32,520 but the most common are GNOME, KDE Plasma, 102 00:04:32,520 --> 00:04:34,620 Cinnamon and MATE. 103 00:04:34,620 --> 00:04:37,440 GNOME is probably the most popular desktop environment 104 00:04:37,440 --> 00:04:40,800 amongst Linux users, and it is free and open source 105 00:04:40,800 --> 00:04:44,130 and powerful and simple to use all at the same time. 106 00:04:44,130 --> 00:04:45,930 Now it's designed from the ground up 107 00:04:45,930 --> 00:04:48,300 to offer Linux desktop users a wonderful 108 00:04:48,300 --> 00:04:50,580 and exciting computing experience. 109 00:04:50,580 --> 00:04:52,620 It presents activities overviews 110 00:04:52,620 --> 00:04:54,990 for easy access of basic tasks. 111 00:04:54,990 --> 00:04:57,300 It provides a powerful search tool for users 112 00:04:57,300 --> 00:04:59,820 who want to access their work from any place. 113 00:04:59,820 --> 00:05:02,610 Inside of GNOME 3, which is the latest stable release 114 00:05:02,610 --> 00:05:03,900 as I'm filming this, 115 00:05:03,900 --> 00:05:05,970 it actually can have distinguished components 116 00:05:05,970 --> 00:05:08,100 and features such that it can support 117 00:05:08,100 --> 00:05:11,520 desktop notifications using convenient messaging systems 118 00:05:11,520 --> 00:05:14,220 enabling on and off switching of desktop notifications 119 00:05:14,220 --> 00:05:15,750 and much more. 120 00:05:15,750 --> 00:05:18,840 The other ones we need to talk about are things like KDE. 121 00:05:18,840 --> 00:05:22,890 Now, KDE Plasma is going to support modularity through widgets 122 00:05:22,890 --> 00:05:26,820 and it enables users to add, move or remove screen elements 123 00:05:26,820 --> 00:05:29,340 to fit their own personal workflows. 124 00:05:29,340 --> 00:05:32,580 KDE Plasma has a robust set of GUI apps as well, 125 00:05:32,580 --> 00:05:35,070 including word processors, mail clients, 126 00:05:35,070 --> 00:05:37,500 multimedia software and more. 127 00:05:37,500 --> 00:05:42,060 Also, KDE Plasma can support both X and Wayland. 128 00:05:42,060 --> 00:05:45,480 Now Cinnamon is actually going to be a fork of GNOME 3 129 00:05:45,480 --> 00:05:47,130 and it's one of the default environments 130 00:05:47,130 --> 00:05:49,260 in the Linux Mint distro. 131 00:05:49,260 --> 00:05:52,740 Cinnamon was developed in response to the changes in GNOME 3 132 00:05:52,740 --> 00:05:54,990 and gives us a typical desktop metaphor 133 00:05:54,990 --> 00:05:57,240 rather than an abstracted model. 134 00:05:57,240 --> 00:05:59,580 Now, the fourth one we have is known as MATE, 135 00:05:59,580 --> 00:06:03,090 and MATE is an intuitive and appealing desktop environment. 136 00:06:03,090 --> 00:06:06,120 It's actually an extension of the older GNOME 2. 137 00:06:06,120 --> 00:06:09,180 It works on Linux and many other Unix-like systems 138 00:06:09,180 --> 00:06:12,000 and it comes with a handful of default applications 139 00:06:12,000 --> 00:06:15,360 such as the Kaha File Manager, Pluma Text Editor, 140 00:06:15,360 --> 00:06:17,790 MATE Terminal, and many others. 141 00:06:17,790 --> 00:06:20,670 Additionally, it's also the default desktop environment 142 00:06:20,670 --> 00:06:23,970 for Linux Mint, alongside Cinnamon's desktop. 143 00:06:23,970 --> 00:06:25,740 None of these desktop environments though 144 00:06:25,740 --> 00:06:28,230 is objectively the right choice. 145 00:06:28,230 --> 00:06:30,150 Which environment you choose to use 146 00:06:30,150 --> 00:06:32,820 is ultimately going to come down to your personal preference 147 00:06:32,820 --> 00:06:34,920 and your comfort level with each one. 148 00:06:34,920 --> 00:06:38,580 Personally, I tend to use either GNOME or KDE, 149 00:06:38,580 --> 00:06:40,320 but that's just because I've been using them 150 00:06:40,320 --> 00:06:42,810 for over two decades now. 151 00:06:42,810 --> 00:06:45,000 When you're starting out, the best thing to do 152 00:06:45,000 --> 00:06:47,640 is to try each environment in order to know which one 153 00:06:47,640 --> 00:06:50,790 is really right for you and which one you like best. 154 00:06:50,790 --> 00:06:53,970 Another concept we need to cover is remote desktop. 155 00:06:53,970 --> 00:06:56,580 Now remote desktop is a concept in which clients 156 00:06:56,580 --> 00:06:59,400 are going to connect to a remote system over a network, 157 00:06:59,400 --> 00:07:00,810 and they want to be able to sign in 158 00:07:00,810 --> 00:07:03,930 and use the desktop environment of that system. 159 00:07:03,930 --> 00:07:05,910 Using remote desktop sessions, 160 00:07:05,910 --> 00:07:07,800 you can actually create a situation 161 00:07:07,800 --> 00:07:10,320 where you can configure a server that has a GUI 162 00:07:10,320 --> 00:07:13,440 but you aren't physically located at that system. 163 00:07:13,440 --> 00:07:15,840 In addition to this, remote desktop sessions 164 00:07:15,840 --> 00:07:17,400 are going to be used in an environment 165 00:07:17,400 --> 00:07:18,570 where the user connects to 166 00:07:18,570 --> 00:07:20,430 and works from the remote computer 167 00:07:20,430 --> 00:07:22,830 as if it was located right in front of them. 168 00:07:22,830 --> 00:07:24,720 In other words, the remote session 169 00:07:24,720 --> 00:07:26,850 becomes their primary desktop. 170 00:07:26,850 --> 00:07:29,700 Now there are many software packages available in Linux 171 00:07:29,700 --> 00:07:32,130 that will provide you with remote desktop sessions. 172 00:07:32,130 --> 00:07:35,340 One of the most popular ones is VNC. 173 00:07:35,340 --> 00:07:38,040 The Virtual Network Computing, or VNC, 174 00:07:38,040 --> 00:07:41,100 is going to be a cross-platform remote desktop service 175 00:07:41,100 --> 00:07:44,220 that enables full remote control of a desktop. 176 00:07:44,220 --> 00:07:48,840 VNC leverages the remote frame buffer or RFB protocol. 177 00:07:48,840 --> 00:07:52,080 A VNC server has to be installed on your target machine 178 00:07:52,080 --> 00:07:53,370 and then you're going to access that 179 00:07:53,370 --> 00:07:55,440 with a corresponding client. 180 00:07:55,440 --> 00:07:58,380 Another one you can use is xrdp, 181 00:07:58,380 --> 00:08:00,510 which is a free and open source utility 182 00:08:00,510 --> 00:08:02,760 that constructs a Remote Desktop Protocol, 183 00:08:02,760 --> 00:08:06,300 or RDP like server, for non-Windows systems. 184 00:08:06,300 --> 00:08:09,810 You can also install xrdp on a remote Linux server 185 00:08:09,810 --> 00:08:13,860 and use a tool like R Desktop or even the default RDP client 186 00:08:13,860 --> 00:08:15,540 to connect to that server. 187 00:08:15,540 --> 00:08:17,880 So in other words, we can now have a client 188 00:08:17,880 --> 00:08:19,470 that can be on any platform 189 00:08:19,470 --> 00:08:22,740 because RDP works on Linux and Windows. 190 00:08:22,740 --> 00:08:25,170 The xrdp utility is designed to work 191 00:08:25,170 --> 00:08:27,840 with the X Windowing System as well. 192 00:08:27,840 --> 00:08:30,540 The next one we have is known as NoMachine. 193 00:08:30,540 --> 00:08:32,789 Now, NoMachine is a cross platform 194 00:08:32,789 --> 00:08:35,970 proprietary remote desktop software, and it offers support 195 00:08:35,970 --> 00:08:39,000 for multi-session environments and account management. 196 00:08:39,000 --> 00:08:42,570 Therefore, NoMachine is actually useful in organizations 197 00:08:42,570 --> 00:08:45,900 with many different users that require simultaneous access 198 00:08:45,900 --> 00:08:47,400 to the same server. 199 00:08:47,400 --> 00:08:50,490 NoMachine is designed to work with X. 200 00:08:50,490 --> 00:08:52,980 Now another one we have is known as Simple Protocol 201 00:08:52,980 --> 00:08:56,550 for Independent Computing Environments, or SPICE. 202 00:08:56,550 --> 00:08:58,950 SPICE is a free and open source protocol 203 00:08:58,950 --> 00:09:02,130 designed specifically for use in virtual environments. 204 00:09:02,130 --> 00:09:04,200 SPICE is often used for administrators 205 00:09:04,200 --> 00:09:06,630 to connect to virtual machines that are being hosted 206 00:09:06,630 --> 00:09:10,920 by kernel based virtual machines or KVM hypervisors. 207 00:09:10,920 --> 00:09:12,480 Another concept we need to cover 208 00:09:12,480 --> 00:09:15,120 is the concept of Console Redirection. 209 00:09:15,120 --> 00:09:18,090 Now Console Redirection is the process of forwarding input 210 00:09:18,090 --> 00:09:20,220 and output through a serial connection 211 00:09:20,220 --> 00:09:22,410 rather than through an I/O peripheral 212 00:09:22,410 --> 00:09:24,420 that's directly attached to the system. 213 00:09:24,420 --> 00:09:26,640 So instead of sending things to and from my mouse 214 00:09:26,640 --> 00:09:30,120 and keyboard, I want to send it through the console instead. 215 00:09:30,120 --> 00:09:32,550 This enables the system with Console Redirection 216 00:09:32,550 --> 00:09:35,280 to send display output along a serial cable 217 00:09:35,280 --> 00:09:37,020 and eventually to a remote client, 218 00:09:37,020 --> 00:09:39,420 instead of sending it right to a monitor. 219 00:09:39,420 --> 00:09:41,700 Likewise, the remote client can also redirect 220 00:09:41,700 --> 00:09:44,130 the keyboard input along a serial connection 221 00:09:44,130 --> 00:09:46,260 and send that to a remote server. 222 00:09:46,260 --> 00:09:49,440 Ultimately, Console Redirection enables administrators 223 00:09:49,440 --> 00:09:52,350 to remotely configure systems in a pre-boot environment 224 00:09:52,350 --> 00:09:54,810 like BIOS or UEFI. 225 00:09:54,810 --> 00:09:57,180 Secure Shell is another remote access protocol 226 00:09:57,180 --> 00:10:00,000 that we can use instead of using remote desktop. 227 00:10:00,000 --> 00:10:02,460 When you're using Secure Shell, or SSH, 228 00:10:02,460 --> 00:10:04,890 it encrypts transmissions over a network 229 00:10:04,890 --> 00:10:07,260 and is by far the most commonly used protocol 230 00:10:07,260 --> 00:10:10,950 for accessing command line interfaces on a Linux server. 231 00:10:10,950 --> 00:10:14,010 You can also use SSH to issue commands to the server 232 00:10:14,010 --> 00:10:15,390 as if you are typing directly 233 00:10:15,390 --> 00:10:17,820 into a command line interface itself. 234 00:10:17,820 --> 00:10:20,490 It can also be used to tunnel and carry other types 235 00:10:20,490 --> 00:10:22,230 of network communication securely, 236 00:10:22,230 --> 00:10:24,870 including remote desktop traffic. 237 00:10:24,870 --> 00:10:27,060 This process is known as tunneling 238 00:10:27,060 --> 00:10:29,730 and you can tunnel an application through SSH 239 00:10:29,730 --> 00:10:31,470 to secure it in transmission 240 00:10:31,470 --> 00:10:34,980 by doing what's known as SSH Port Forwarding. 241 00:10:34,980 --> 00:10:36,720 When you're doing local forwarding, 242 00:10:36,720 --> 00:10:38,730 the local client is going to listen for connections 243 00:10:38,730 --> 00:10:41,520 on a port and then tunnels any active connection 244 00:10:41,520 --> 00:10:44,160 to the remote server over SSH. 245 00:10:44,160 --> 00:10:47,250 For example, let's say you want to remotely access a system 246 00:10:47,250 --> 00:10:50,340 over the internet using something like VNC. 247 00:10:50,340 --> 00:10:53,190 Well, VNC is not encrypted by default, 248 00:10:53,190 --> 00:10:55,170 so if you connect to a VNC server 249 00:10:55,170 --> 00:10:58,500 with your local VNC client, that traffic will be sent 250 00:10:58,500 --> 00:11:01,410 in the clear and people could see what you're typing. 251 00:11:01,410 --> 00:11:04,230 But if you forward it through SSH first, 252 00:11:04,230 --> 00:11:07,560 you are now encrypting that traffic and securing it. 253 00:11:07,560 --> 00:11:10,020 In remote forwarding, the SSH server 254 00:11:10,020 --> 00:11:12,180 is going to forward inbound client traffic 255 00:11:12,180 --> 00:11:14,580 to another system on a different port. 256 00:11:14,580 --> 00:11:17,610 Let's say I set up a VNC server on a local system 257 00:11:17,610 --> 00:11:19,350 and I'm forwarding all VNC traffic 258 00:11:19,350 --> 00:11:21,360 to a port on a remote client. 259 00:11:21,360 --> 00:11:23,310 Whenever the remote client connects to this port 260 00:11:23,310 --> 00:11:25,830 using the local host, they can then establish 261 00:11:25,830 --> 00:11:29,190 a remote desktop connection with the local server. 262 00:11:29,190 --> 00:11:32,160 X and X11 are both network aware, 263 00:11:32,160 --> 00:11:34,110 and so you can actually enable these clients 264 00:11:34,110 --> 00:11:37,350 to access GUI elements over a network too. 265 00:11:37,350 --> 00:11:39,030 But if you want to do that, 266 00:11:39,030 --> 00:11:41,280 you definitely need to forward your X traffic 267 00:11:41,280 --> 00:11:44,220 and X11 traffic through an SSH tunnel 268 00:11:44,220 --> 00:11:46,710 to ensure they're encrypted before communicating them 269 00:11:46,710 --> 00:11:48,213 over an unsecure network. 270 00:11:49,050 --> 00:11:52,050 Another thing we need to talk about is accessibility. 271 00:11:52,050 --> 00:11:53,610 Now each desktop environment 272 00:11:53,610 --> 00:11:55,620 has its own accessibility options 273 00:11:55,620 --> 00:11:58,020 to accommodate people with disabilities. 274 00:11:58,020 --> 00:12:00,000 Some options include a screen reader 275 00:12:00,000 --> 00:12:02,250 that reads all the highlighted screen elements. 276 00:12:02,250 --> 00:12:04,320 You might have a magnifier that zooms in 277 00:12:04,320 --> 00:12:06,480 on specific sections of your screen. 278 00:12:06,480 --> 00:12:08,970 You can also increase the size of specific elements, 279 00:12:08,970 --> 00:12:12,090 like the text or the buttons or the mouse pointers. 280 00:12:12,090 --> 00:12:14,610 And you can even use an onscreen keyboard 281 00:12:14,610 --> 00:12:17,790 that enables users to click to type text using your mouse 282 00:12:17,790 --> 00:12:20,370 instead of using a physical keyboard. 283 00:12:20,370 --> 00:12:23,220 Also, we have keyboard accessibility options 284 00:12:23,220 --> 00:12:25,170 including things like Sticky Keys 285 00:12:25,170 --> 00:12:27,690 which enables users to press one key at a time 286 00:12:27,690 --> 00:12:30,090 instead of having to hold down multiple keys at once 287 00:12:30,090 --> 00:12:32,580 in order to activate keyboard shortcuts. 288 00:12:32,580 --> 00:12:35,070 We also have Repeat Keys, which enables the user 289 00:12:35,070 --> 00:12:38,310 to hold down a key in order for it to be repeatedly entered. 290 00:12:38,310 --> 00:12:40,020 And we have Toggle Keys, 291 00:12:40,020 --> 00:12:41,670 which enables the system to beep 292 00:12:41,670 --> 00:12:43,980 whenever keys like Caps Lock or Num Lock 293 00:12:43,980 --> 00:12:45,690 are going to be pressed. 294 00:12:45,690 --> 00:12:48,180 Finally, we can also use visual themes 295 00:12:48,180 --> 00:12:51,120 like high contrast to make the screen easier to read 296 00:12:51,120 --> 00:12:53,610 for certain people with visual impairments. 297 00:12:53,610 --> 00:12:54,720 There are lots of different ways 298 00:12:54,720 --> 00:12:56,820 that we can make our systems more accessible 299 00:12:56,820 --> 00:12:58,833 and better suited for our end users.