A computer without a program running on it is just a hunk of hardware. 0:00 Hardware is anything that's well, hard, like a desktop, tablet, or smartphone. 0:04 In order for a piece of hardware to do anything, it has to run programs. 0:10 In order for 0:14 programs to work, they need to be written in a way a computer can understand. 0:15 This is where binary and data come into play. 0:20 Programs themselves and what you create when using them are all stored as data, 0:23 which are just a lot of binary digits, ones and zeroes. 0:27 [SOUND] One of the first programs you see when you turn on [SOUND] your computer is 0:31 the operating [SOUND] system. 0:35 The job of the operating system is to help all [SOUND] other computer programs work 0:37 by handling the messy details of controlling the computer's hardware. 0:42 [SOUND] The operating system is the core software component of a computer and 0:46 provides an interface between the [SOUND] hardware and the software. 0:50 Say, for example, you wanted to open an application. 0:54 You would have to click on it either with your mouse or tap it with your finger. 0:57 That click or [SOUND] touch is called an event. 1:02 [SOUND] When you send that click through your mouse, touchscreen or 1:05 keyboard, it's the operating system's job to watch for that event. 1:09 [SOUND] When you click an application, part of the operating system's job is to 1:13 stash the mouse click's information in memory until it can be processed. 1:18 In addition to storing events as data, applications are data, and what's inside 1:22 those applications are data, like documents, photographs, video, and music. 1:27 In order to save all this data, 1:32 your computer uses a few different types of electronic storage depending on 1:34 the priority and type of data you want to store. 1:39 To store data into memory in an efficient way, 1:41 there are a few different types of memory to choose from. 1:44 RAM and virtual memory are temporary storage areas. 1:48 And a ROM and hard drives are permanent storage areas. 1:52 Let's see an example of how these work. 1:55 [SOUND] From the moment you turn your computer on to the moment you turn it off, 1:58 your computer is constantly using memory. 2:03 When you turn on your [SOUND] computer and it loads the operating system, 2:05 it's usually loading this from the hard drive to the system's RAM. 2:10 This allows the central processing unit, or CPU, to [SOUND] have immediate access 2:14 to the operating system, which enhances the overall performance and functionality. 2:19 Similarity, when you open an application, it's loaded into RAM. 2:25 In order to conserve RAM usage, 2:30 many [SOUND] applications load only the essential parts of the program at first. 2:31 It will only load other [SOUND] pieces when you ask for them. 2:36 Say you click on the Word application on your computer. 2:39 Your [SOUND] operating system receives that request and Word is loaded into RAM. 2:43 [SOUND] Then you want to open up a story you're writing. 2:47 When you click on your story document, that file's then loaded into RAM. 2:50 After reading for awhile, you make some changes and then [SOUND] save your work. 2:55 When you save, the edited [SOUND] file is written to the specified storage device. 2:59 [SOUND] If you don't save your work, 3:04 it won't transfer the data to a more permanent storage area. 3:06 And it will be lost if you suddenly [SOUND] quit the application or 3:10 it crashes. 3:14 When you exit Word, [SOUND] the application and any 3:15 documents are purged from RAM in order to make room for new applications and data. 3:18 [SOUND] This repeated quick-loading and 3:24 emptying is why is RAM is a temporary storage area. 3:27 [SOUND] I'm always curious about what these things actually look like, so 3:30 let's check out the teardown on ifixit.com. 3:34 I'm going to be using the Macbook Pro teardown to show you 3:37 what computers look like, but it's always good to look at the device you're using. 3:40 When you get a chance, search for the teardown of your own device. 3:45 If you get the chance to deconstruct a computer at home, 3:48 remember to disconnect your device from any power supply. 3:51 And disconnect and remove the battery as soon as you can get to it. 3:55 Okay. 3:59 Now that I'm finished with my PSA, 3:59 let's check out the teardown of my computer a MacBook Pro. 4:01 Right after they disconnect the battery, the first thing they remove is the RAM. 4:05 Remember this is the fast temporary storage nearly all data goes through. 4:10 Next they remove the hard drive. 4:16 Let's jump over to a teardown of the hard drive so we can see inside. 4:18 Here we can see there's a large disk or 4:23 a few large disks called platters and a read-write arm. 4:26 Hard drives store memory using magnetism. 4:30 Each large disk in a hard drive is divided into billions of 4:34 tiny areas that can each be independently magnetized or 4:38 demagnetized to store either a one or a zero. 4:42 Magnetism is used in computer storage because each of these tiny 4:46 areas remain magnetized or demagnetized even when the power is switched off, 4:49 permanently storing the data. 4:55 The reason why we don’t use this kind of storage all the time is because it’s 4:57 relatively slow compared to RAM. 5:00 And if you always had to load programs directly from your hard drive, 5:02 the overall performance of your computer would be terribly slow. 5:06 [SOUND] Hopefully, this gives you a good understanding of data and 5:10 where it's stored in the computer. 5:14 In the next stage, we'll leave hardware behind and 5:16 talk about software and programming. 5:18 To do this, we'll explore the fundamentals of computer software, 5:21 learn about a few programming languages, and figure out how they work together. 5:25