 Welcome back everyone. Today we're going to give an introduction into computer hardware. So this is a CPU. CPUs are really complicated actually. And they're super interesting, but we're not going to get too much into them. Basically, CPUs have extremely tiny capacitors inside. And the more capacitors you can fit inside a CPU, the faster or the basically the better it works, the faster it works. A CPU, its whole job is to process. It's basically a very simple calculator. You can think of it like a calculator. So all of the data in the computer needs calculations to know what that data, what we should do with that data. So for example, to even show the mouse on my screen or even to show this screen, the processing unit is processing data and then outputting basically the command to the video card to show this on my screen. So the central processing unit is kind of like a calculator that does all of the calculations and says, okay, this is the output that you need to put onto the screen. And then it sends that through a bus. The graphics card processes that output or interprets that output and outputs that to your screen. Or if I move my mouse, then the processor says, hey, the mouse is moving, I need to move the mouse on the screen as well. So the processor basically computes and commands everything in the computer, what it should do and how it should work. These sticks are sticks of random access memory. Random access memory is you can think of it like almost like a notebook, right? So if you're trying to do math, and you have a really complicated problem, then you can write down the math problem in a notebook. And then you can work on different parts of the problem in your head, and then write the answer to certain parts of the problem, and then maybe write down a number in your notebook and then get another part of the problem work on the other part of the problem, write that down in your notebook and things like that. So you're not working on the entire problem at the same time. And your notebook is kind of like a temporary storage space for the math problem. And in computers, it's exactly the same. So RAM acts as a very fast temporary storage, fast temporary storage. So we load data into RAM, and then the processor takes parts of the data and does calculations with it, and basically sends the data back and forth between memory while it's working on it. So RAM is a temporary working space to hold programs or program data for the processor to work on. Now, what kinds of things are loaded into memory? Well, any application that you're running in your computer, the data has to be loaded into memory, that way the processor can work on it. So if you load KakaoTalk or you load Microsoft PowerPoint or something like that, that program's data is loaded into RAM, and then the processor can work with that data and configure it to how it should work. Yeah, so RAM is just like a temporary working space that can hold certain amounts of data for the processor to work on. Other things that are inside RAM are like passwords. So anything you type into your keyboard also goes into memory. So a lot of criminals steal data, like credit cards or passwords or things like that, by looking at your memory and trying to collect memory that has maybe sensitive or secret information. If you open up a picture on your computer, then that picture's data is loaded into RAM, that way the processor can use it. So basically everything that we run on our computer is loaded into RAM. Now, where is the data coming from? Well, the data is coming from hard drives. We store data on hard drives, and that if we shut our computers off, hard drives can keep the data for a very long time. If we shut the computer off, RAM is cleared out. RAM only works whenever the computer is on and has power. Hard drives store the data for a very long time, even if there is no power. Now, this type of hard drive is called a hard disk drive. So if you look into your computer, you'll probably see this kind of big square-ish box, okay? And inside this big square, well, first off, this box is the hard drive itself. There's kind of a protective container on the outside. You do not open up these hard drives. This is a SATA connector that would connect directly to the keyboard, and then these are jumpers that tell the hard drive a little bit about how it should be configured. But basically, we just plug in a SATA connector, and that's it. Yeah, SATA connector to the motherboard, and then the motherboard would be able to see the hard drive. Now, if we did open up this case, then inside we would see a bunch of disks. They kind of look like CDs, but they're just made of metal. So in a hard disk drive, we store data magnetically. So you can see this arm, and this arm has a head. And basically, this arm and head can change the magnetic fields on this metal disk. And by changing the magnetic fields, we can store ones and zeros or data. So your hard drive is storing, most likely, on desktop computers, your hard drive is a hard disk drive. They're relatively cheap to store a large amount of data, but these are very slow. So RAM, for example, is very fast storage, but it's very expensive. Hard drives are very slow storage, but they're very cheap. So we use a combination. We use hard drives to save the data, and then whenever we need the data, we pull the data from the hard drive and load it into memory. And basically, we just read magnetic signals off of these platters or these disks. Another type of hard drive that's newer and faster but also more expensive are solid state disks. And inside its case, it looks something like this. This is also a SATA connector or E-SATA connector to the motherboard, or SATA connector, sorry, the SATA connector to the motherboard. This is inside a case. If we open that up, then it just looks like chips. There's no moving parts where if we go back, these disks spin. And because they spin, there's a lot of moving parts, like this arm will actually move back and forth, and these disks will spin. On solid state disks, nothing moves. It's just chips. But it's also more expensive to use. It's also more expensive to store data inside these chips. Now, both of them work pretty well. Hard disk drives will store data a little bit longer, but it's possible that some of these motors break relatively quickly. On solid state disks, sometimes the chips, if you keep using the chip over and over and over again a lot of times, then the chips will start to go bad. So if you have a hard drive where you have to write a lot of data over and over again, hard disk drives are probably a little bit better, but they're slower. Solid state drives are really good if you're writing data really quickly and you don't change the data very often. But they're both pretty commonly used now, and most people keep their computers for maybe two to five years. So it's unlikely that a solid state drive is going to go bad that quickly. Next is a video card. This is a newer type of video card, and it basically is almost another computer inside your computer that focuses only on video. So whenever we go back, I'm going to go back a little bit, the processor that we have in our computer normally is what we call a general processor. It's used for general processing. That means that it can handle a bunch of different problems, but it's not really good at solving any of the problems. Now, processors are quick, but it's used for general purpose processing. That means that any problem that it gets, it should be able to handle. Now, if we go back to video processors, these video cards that we put inside an expansion slot, these video cards have their own processor inside. So this is a video card with a case, this is without the case, and you see this processor in the middle here. This processor is specifically designed to do math for video. So it is really, really good at doing extremely fast math calculations, but it would be really bad at running KakaoTalk, right? Because KakaoTalk is not video intensive. So its processor would be really bad at running something like KakaoTalk, but it would be really good at running extremely realistic graphics or rainfall or something like that. So there's a processor, and this processor is specifically designed to render video. So we can use this for a lot of different things. Basically, it's extremely fast at math calculations. Now, if we look at the back of it, there's a couple of different connectors. These are, it looks like a 2DMI connectors and then an HDMI connector, and then I'm not sure what this one is, but there's at least three monitors that I can plug into this video card. So you would plug this video card into your motherboard. The motherboard would detect that a new video card is available, and it would try to figure out what features this video card has, and then we could connect three monitors or more to this video card. Now, video card's basically just almost like a separate computer because it has its own processor, it has its own even RAM, but it's not good for general purpose processing. Now, what you'll notice from all of this is if I look at the motherboard, I can change the processor, I can change RAM, I can change hard drives, I can change video cards. So if you buy a computer, you can upgrade all of these components, and that was the original idea, actually. Most people don't upgrade their computers, they just buy a new computer whenever their old one gets old, but if you take your desktop computer apart, you can put a new processor in that's faster. You can put in more RAM, you can put in a new graphics card, you can put in new hard drives or more hard drives. So the idea of computers originally was to upgrade them, not throw everything away, because computers used to be really really expensive. Now, especially with consumer computers, people don't tend to upgrade their computers very often, but you can, and it's usually sometimes a little bit cheaper to upgrade it. So for example, more RAM might help your computer run much faster, and then you don't, you can spend maybe a hundred dollars instead of spending, you know, a thousand dollars for a new computer. Okay, so computers were made to be upgraded, and all of these components can be taken out of the motherboard, and you can add better ones in. Okay, now that's for desktop computers. For laptops, it's a little bit different. Most laptops, you can upgrade them at least a little bit, but laptops are more compact, much smaller. So for example, this is one of HP's extremely thin laptops, and it would be very difficult to upgrade this laptop without HP's own parts, basically. Now, if you notice, on a laptop, we have all of the same things as a desktop. So on the side here, we have speakers, we have a keyboard, we have a mouse pad, we have a monitor, and then on this, we also have microphone and camera. So microphone and camera, microphone and camera, input, keyboard input, mouse pad input, speakers output, display output, okay, but the computer itself has all of the same components. So let's look inside a laptop. So inside this laptop, and basically the monitor would, or the display would be about which side? Actually, I think the display is, it's probably closed and it's on top of it. So the display, this is the bottom of the laptop. This is where the battery would be. This is actually a relatively high-end gaming laptop. So this is for air circulation. Remember, the computer gets really, really hot, and this is a very high-end fan to make sure that the computer doesn't get very hot. This card right here is probably the GPU. Now, think about the GPU we just saw. This GPU is really, really big, right? But it fits inside a big computer case. This GPU is much smaller and maybe a little bit less powerful, but still quite powerful GPU. Here, what do we have over here? The processor is probably underneath here, I'm guessing, and then the RAM is here. Now, the RAM for a laptop is about half the size, maybe a little bit less than for a big computer, but it's about the same speed, okay? Processor is about the same size, maybe a little bit less, and then I'm not sure what exactly this chip is. I can't really see it too well, okay? So we have the GPU, we have RAM, we have the processor, we have a fan and heat sink, and then here is a hard drive, and this is a, it looks like a hard disk drive. So the hard disk drive that we saw for the computer is actually quite big, but the hard disk drive that we put inside a laptop is actually very, very small. So that's why laptops tend to have smaller size, capacity hard drives than computers or big computers, because the space or the size of the disk must be much smaller. So we have storage, we have RAM, we have processor, we have GPU, we have fan, okay? And then we have power, but the power is not in there right now. So all of it exactly the same components as a desktop computer, except in much smaller size. So with a laptop, it's a little bit harder to change components. You can change RAM pretty easily, you can change hard drive pretty easily, but changing the processor, changing the GPU, it's a little bit more complicated. Okay, and this brings us to phones. So are smartphones, computers? Yep, definitely, okay? So this is an iPhone, yeah, just a newer iPhone and newer Samsung. I don't know what this is. Maybe a s, I don't know, six, three, six, five, something like that. I don't know. So a Samsung phone and an iPhone. And let's take a look on the inside. So this is an iPhone from the inside. It has a battery and the battery takes up most of the phone's size and capacity, right? The battery is pretty much everything. If we take the battery out, there's, I don't think there's anything behind the battery. The entire phone, all of the processor, all of the RAM and all of the hard drive is in this chip right here. So this chip on basically above and to the side of the phone, this is one single chip. And that's essentially the entire iPhone is just this chip. And everything that we put inside the desktop computer is inside this compact form. So really, really tiny. That's why, well, that's one reason why phones are so expensive is because if we make chips really big, then they're easier to work with. We don't have to use really complicated, well, as complicated manufacturing methods. But if chips are really, really small, then we have to use more complicated methods to create these chips. So part of the expense of a phone is making these chips so small. Now that being said, you can probably produce a phone. If you were just building this phone, if you could just get the raw parts, it probably costs maybe, I don't know, $100, maybe less than that to make a phone. And then there's all of the cost of advertisements and stuff like that. But and research and development, all those things. But the actual cost to make this, especially in the millions of units, is relatively low. Down here is what they use, I believe, for the touch display, kind of a processor for touch display. And then some of this is just where power comes in, power converters and chip. Yeah. So this is the inside of an iPhone. The chip is actually really, really small. If we look closer at the iPhone chip, there's the camera. So this is a controller for the camera. And then all of this is, I don't even know which part is which, but basically all of this is the RAM, hard drive and processing unit. So everything is inside this chip that you would put inside a desktop computer. Now look how tiny these capacitors are. The manufacturing for these is very difficult and it takes a lot of research and a lot to get it working, basically. Now for the Samsung, same thing, you basically have the back end and then the case. And inside the case, there's not a lot of electronics. A lot of this is for, for example, the connectors for the headphones, connectors for power, connectors for, I think, the speaker. So this is a controller unit for the inputs on the bottom of the phone. And then all of the processing unit, processing unit, RAM and hard drive, internal hard drive is all in here. So this is a very, very small unit. And this is the entire computer. It looks very tiny, but it is super, super complicated. And that's why, one reason why it's so expensive. And basically upgrading this and making the circuitry better is why people are always coming out with new phones. So from a big computer to a laptop to a smartphone, all computers have some sort of processing unit, most likely some sort of RAM or temporary storage, and then most likely some sort of hard drive or long term storage. Hard drive and long term storage tends to work without power. And it keeps for a very long time. Temporary storage, like RAM, you have to have power to keep data in RAM. And then the processing unit speaks directly to RAM to be able to work on the data that needs to work with. So that's, I think, pretty much it. Yep, that's it for computer hardware and looking into a computer, a laptop and your smartphones. That's it for today. Thank you very much.