In today's lesson we're going to discuss Linux distributions.
So Linux distributions are anything that contains the Linux kernel.
So we're going to be discussing about the,
little bit about the kernel,
and how distributions work.
What types of distributions there are out there
and a little bit about how we can build our own distribution, if we want to.
So in order to be called Linux,
again we have to have the Linux kernel.
We have different forks of the Linux kernel.
We could run version 2,
version 3, all kinds of different versions out there.
So the kernel is constantly being updated by hundreds of developers all over the world.
I said it in the previous video,
but Linus Torvalds still is one of the primary contributors to the kernel.
The kernel is the core of the operating system.
It is what makes Linux, Linux.
It has different modules built in and ways that it interacts with hardware,
to really make it an operating system.
So each distribution of Linux has its own kernel,
and it usually has a package management system that is used
for building other software on top of that kernel,
to make what we call an operating system that you would use for different applications.
So, some distributions may be heavily focused on web content.
Some of them may be focused on security.
Some are forensic software.
We can do all kinds of stuff with our Linux distributions.
There are literally thousands of distributions
out there because people can make their own.
So developers out there create all different forks.
I personally run, probably around seven or eight different distributions,
at my home or even at my desk,
I probably have 15, 20 different distributions used for different things.
Now, all those working together,
I use virtualization technology to run them all at the same time,
but let's say I want to execute a virus,
while I use a certain Linux distribution to make sure I don't infect
my main system or penetration testing,
for example, as another distribution or if I want to bring up a web server.
Okay. All those distributions are custom built by people that
have very specific criteria in mind
about what they want to do with that operating system.
So a distribution may also include,
including the kernel, open source tools and libraries.
A Window Manager, a Window Manager is a GUI interface to the the operating system,
and how we actually interact with the kernel.
So maybe we don't have a GUI,
we start to have a Windows Manager to interact.
Also, a desktop environment, as well.
So a desktop environments may include such versions as like
KDE or Gnome or XFCE or Flux,
there's a whole lot of them,
depending on how easy they are to use.
So while most distributions are open source,
meaning that anybody can use them,
some of them aren't.
So Red Hat, for example Red Hat Enterprise Linux or you may hear it RHEL... R-H-E-L,
those distributions are paid for because of the support that they have behind them.
So, if we have an issue with our Red Hat systems,
we may call up support and say how does this work.
The benefit of having support behind some of
those enterprise systems is because we know they're maintained.
We know that the security patches are always going to be there.
They're always working together,
to come up with a solution that works for that operating system.
So how do we decide on which distribution is right for us?
Well, really it comes down to what you want to do with it.
What I said before,
we have security distributions,
we have forensics distributions,
we have normal computing desktop,
web server, networking, we can run firewall distributions,
we can run all kinds of stuff.
So we need to find which one is going to be best for us,
to use in a certain used case.
Some other considerations are also, what about support.
So, some of the distributions out there are much more supported than others.
So Red Hat being the one that's going to be the
most supported out there, yet costs money.
Ubuntu has also come out with what they,
so they release two distributions every year,
so they release a version in October,
and they release a version in April.
So for this year, for example,
2017 they'll come out with 17.04 and 17.10.
So in the even number of years,
they release long term support distributions,
meaning that, whatever they develop for
that operating system and integrate the packages that work with it,
will be supported for many years.
So the off... the odd years or the off schedule ones.
So like 16.04 for example was a long term support or LTS version of Ubuntu.
So depending on if we need support or not,
goes back to how long do we want to use this thing.
Does the distribution stay up to date on certain packages?
Because Linux is open source,
and a lot of versions are open source,
it really comes down to,
are the developers constantly evaluating the patches.
And how difficult is the diffs,
excuse me, the distributions to use?
If it's clunky, it doesn't make sense with the hardware we have it on.
If it doesn't work with virtual machines,
maybe it's not a good distribution for us to use.
Additionally, do we really want a GUI interface on a web server?
Probably not, because we're going to be using a command line only.
We need to have these considerations in mind,
before we deploy a distribution.
So the major distributions,
distrowatch.com has a lot of information on all kinds of distributions.
There is something being released all the time.
Some major distributions include Red Hat flavors like Fedora and Scientific Linux,
and CentOS also pronounced Centos,
depending on who you talk to.
CentOS is a 100% compatible version of Red Hat.
It's just open source.
Debian also includes versions like Ubuntu or Knoppix or even Mint.
Somebody that wants to get into Linux,
just for testing it out,
and for using it as a desktop may use Mint because it has a lot of drivers in there,
that we can use to watch video, for example.
You want to use it for your home computer.
It's a great way to dive into Linux.
We also have Arch and Gentoo and Slackware.
So custom examples of Linux distributions,
Android for your phones, routers, DDWRT,
for security we have Kali Linux,
for the Internet of Things,
Nest, Raspberry Pi, and for privacy,
Tails Linux, for example.
So in conclusion, Linux distributions come in all shapes and sizes.
Some are large, some are small,
it's really up to the system administrator to
decide what is the best distribution for us.