Hi. So, within the previous lectures, we have seen many folders inside of the Linux root folder. When we open the file system, we have seen many things like etc, home, mnt, run, stuff like that. So, we need to understand what they do and how they are configured, how they are structured. So, if you open the file system, we can see all the files and folders that I'm talking about. So, make sure you're in the file system, and you should be seeing all this. So, this is the Linux foldering system and it's not only for Kali Linux, it's still more or less the same in other Linux distributions as well. So, we need to understand what goes on inside of those things. So, it's a little bit different architecture than the Windows. Actually, it's a lot different because, assume that you're actually installing a programme or a software inside of Windows, right? It just goes under programme files or whatever you may want to state over there. But in the Linux, it can go into multiple folders. For example, in the bin folder over here, you see the binaries, okay? So, these are the programmes, these are the softwares that you execute. For example, when you write ls or the other comments like this, here you go, there is ls inside of the bin folder. So, when you type ls inside of terminal it executes that binary by looking at this bin folder. But you can find some different files and folders or configurations of ls in other folders. So, ls can just sit in there, and this is just an example. But when we look at the sbin for example, this is system binaries. So, a lot of things that root executes are located inside of this sbin folder. So, maybe ls does not have any configuration, but the other files and other systems can have configurations scattered around these folders depending on what they are. So, it's different than Windows. And in fact, it doesn't create any difference for us, because we will see the package managers in the next lecture. It's very easy to install a software inside of Kali Linux, but you need to understand how it works in background, right? So, it actually scatters the files and folders depending on what they are, depending on the structure that has been created for us over here. So, let's try to look at some of these folders, and at least try to understand what goes inside of those. For example, we have etc or dev over here. For example, inside of dev, there are files regarding to hardware like disk files and something. Inside of etc, we have configuration files. Again, a binary can be in the bin folder or any other folder that you have installed it to, but maybe the configuration files of that binary can be sitting in the etc. So, we're going to use etc a lot during the course, and we're going to use many of them, by the way. But you need to understand why we are using them. Okay, that's why we are having this lecture. And you may come across this kind of questions in cybersecurity interviews, by the way, they can ask you what's an etc? What's a var folder? So, let's go to the var folder while we speak of it. var stands for variable. So, we actually store some kind of variable files over here like log files. And we also have the web server inside of this var folder as well. So, we're going to be using this var folder a lot for the www folder. Here you go, that's the one that I'm looking for. And this is the web server file folder that we will be using a lot during this class. So, after var, maybe we can go to tmp which stands for temporary. So, if binary creates a temporary file and folder, they can store it in the tmp folder. They do not necessarily have to store it over here, but it's the main convention, as you can see, they're temporary folders over there. So, maybe they will get deleted automatically after they're done. So, home folder, we have already seen this. We actually store the user folders inside of the home folder. Right now, I see the Kali, maybe you're seeing something else. But also, we have the root user folder over here, which can be accessed by only the root user as we have seen before. Root folder can be like the separate from the other users in the root folder root of the file system, so that it can be differentiated as well, as in this case. So, there is a proc folder and mnt folder right next to them. proc stores the process information and mnt stores the temporary mounted, for example, I believe there's nothing over here. Okay, let's go to media. There is a media folder over there. Media, actually, it isn't media like pictures and stuff, it's drivers and USBs and CD-ROMs and stuff inside of the media folder. So right now, I believe we don't have anything other than the CD-ROMs that comes like pre-defined over here. So, let's see. We have boot. Of course, this is for booting the Kali Linux. We generally don't want to delete that or any temperment with that. So, we just leave it as it is. So, let's see, we have a service folder over here. srv folder. You may find it over here. So, we store the information services running inside of Kali Linux over there. So, you don't have to go into those folders and do something, but you need to understand what they do because we're going to be using those things a lot. So, let's go and find something, yeah, usr, u-s-r. So generally, we store the files that is going to be... or the binaries, that is going to be created or used by users under this folder. But again, this is not something that is mandatory. There is an opt folder that we can use for optional softwares, optional tools, so we can actually install stuff rather than usr to the opt folder as well. So, we're going to be using those kind of folders in the upcoming lectures, and you will see what I mean. But you need to understand why we're doing it. So, I'm just showing you all of those stuff. So, there are some library folders over there. Again, we don't have to go into library folders or download something to put it over there. But you see what I mean. So, there is a collection of folders, and every folder has its own meaning, has its own purpose. It's not mandatory in many cases, but we're going to be using them. So, I believe it was vital for you to understand that. Let's stop here, and let's go do something more fun in the next lecture.