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‫Instructor: Hi.

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‫So within the previous lectures

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‫we have seen many folders

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‫inside of the Linux root folder, right,

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‫when we opened the file system.

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‫We have seen many things like etc, home,

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‫mnt, run, stuff like that.

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‫So we need to understand what they do

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‫and how they are configured or how they are structured.

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‫So if you open the file system

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‫we can see all the files and folders that I'm talking about.

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‫So make sure you're in the file system

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‫and you should be seeing all this.

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‫So this is the Linux foldering system

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‫and it's not only for Kali Linux,

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‫it's still more or less the same

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‫in other Linux distributions as well.

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‫So we need to understand what goes on

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‫inside of those things.

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‫So it's a little bit different architecture

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‫than the Windows.

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‫Actually, it's a lot different

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‫because assume that you're actually installing a program

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‫or a software inside of Windows, right?

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‫It just goes under program files,

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‫or whatever you may want to state over there.

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‫But in the Linux it can go into multiple folders.

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‫For example, in the bin folder over here

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‫you see the binaries. Okay?

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‫So these are the programs,

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‫these are the softwares that you execute.

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‫For example, when you write ls,

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‫or the other comments like this, here you go,

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‫there is ls inside of the bin folder.

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‫So when you type ls inside of Terminal

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‫it executes that binary by looking at this bin folder, okay?

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‫But you can find some different files and folders

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‫or configurations of ls in other folders.

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‫So ls can just sit in there, ls is just an example.

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‫But, when we look at the sbin, for example,

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‫this is system binaries.

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‫So a lot of things that root executes

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‫are located inside of this sbin folder.

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‫So maybe ls does not have any configuration

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‫but the other files and other systems

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‫can have configurations scattered around these folders

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‫depending on what they are.

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‫So it's different than Windows.

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‫And in fact, it doesn't create any difference for us

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‫because we will see the package managers

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‫in the next lecture.

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‫It's very easy to install a software inside of Kali Linux

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‫but you need to understand how it works

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‫in background, right?

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‫So, it actually scatters the files and folders

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‫depending on what they are,

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‫depending on the structure

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‫that has been created for us over here.

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‫So, let's try to look at some of these folders

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‫and at least try to understand what goes inside of those.

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‫For example, we have etc or dev over here.

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‫For example, inside of dev there are files

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‫regarding to hardware like disc files and something.

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‫And inside of etc we have configuration files.

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‫Again, a binary can be in the bin folder

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‫or any other folder that you have installed it to

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‫but maybe the configuration files of that binary

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‫can be sitting in the etc.

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‫So we're gonna use etc a lot during the course

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‫and we're gonna use many of them by the way,

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‫but you need to understand why we are using them, okay?

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‫That's why we are having this lecture.

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‫And you may come across this kind of questions

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‫in cyber security interviews by the way,

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‫they can ask you, what's an etc?

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‫What's a var folder? Okay?

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‫So, let's go to the var folder while we speak of it.

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‫var stands for variables.

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‫So we actually store some kind of variable files over here

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‫like log files, and we also have the web server

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‫inside of this var folder as well.

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‫So we're gonna be using this var folder a lot

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‫for the www folder. Here you go.

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‫That's the one that I'm looking for.

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‫And this is the web server file folder

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‫that we will be using a lot during this class.

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‫So after var, maybe we can go to tmp,

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‫which stands for temporary.

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‫So, if Binary creates a temporary file and folder

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‫they can store it in the tmp folder.

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‫They do not necessarily have to store it over here

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‫but it's the main convention as you can see.

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‫There are temporary folders over there.

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‫So maybe they will get deleted automatically

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‫after they're done.

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‫So home folder, we have already seen this.

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‫We actually store the user folders

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‫inside of the home folder.

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‫Right now, I see the Kali,

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‫maybe you are seeing something else.

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‫But also, we have the root user folder over here

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‫which can be accessed by only the root user

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‫as we have seen before. Okay.

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‫Root folder can be like the separated

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‫from the other users in the root folder

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‫root of the file system,

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‫so that it can be differentiated as well as in this case.

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‫So there is a proc folder and mnt folder

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‫right next to them.

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‫Proc stores the process information

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‫and mnt stores the temporary mounted, for example.

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‫I believe there's nothing over here.

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‫Okay, let's go to like, media.

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‫There is a media folder over there.

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‫Media, actually, it isn't media like pictures and stuff.

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‫It's drivers and USBs and CD ROMS and stuff

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‫inside of the media folder. Okay?

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‫So right now I believe you don't have anything

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‫other than the CD ROMS that comes like predefined over here.

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‫So let's see, we have boot, of course,

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‫this is for booting the Kali Linux, okay?

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‫We generally don't wanna delete that

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‫or any temperament with that, so we just leave it as it is.

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‫So, let's see, we have a service folder over here,

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‫srv folder. You may find it over here.

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‫So, we store the service information,

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‫services running inside of Kali Linux over there.

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‫So you don't have to go into those folders and do something

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‫but you need to understand what they do

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‫'cause we're gonna be using those things a lot. Okay?

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‫So, let's go and find something.

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‫Yeah, user or usr.

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‫So generally we store the files that is going to be

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‫or the binaries that is going to be created

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‫or used by users under this folder.

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‫But again, this is not something that is mandatory, okay?

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‫There is an opt folder that we can use

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‫for optional softwares, optional tools.

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‫So we can actually install stuff

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‫rather than usr to the opt folder as well.

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‫So, we are going to be using those kind of folders

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‫in the upcoming lectures and you will see what I mean

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‫but you need to understand why we are doing it.

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‫So, I'm just showing you all of those stuff.

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‫So there are some library folders over there.

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‫Again, we don't have to go into library folders

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‫or download something to put it over there,

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‫but you see what I mean.

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‫So there is a collection of folders

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‫and every folder has its own meaning, has its own purpose.

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‫It's not mandatory in many cases

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‫but we're going to be using them,

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‫so I believe it was vital for you to understand that.

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‫Let's stop here and let's go do something

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‫more fun in the next lecture.