Lecturer: In this lesson,
we're going to talk about web servers.
Now, web servers is any server
that provides you access to be able to access a website.
And generally this is going to be done using HTTP or HTTPS,
this stands for the hyper text transfer protocol
or hyper text transfer protocol secure.
HTTP operates over Port 80
and HTTPS operates over Port 443.
Really, they work the exact same way
with one major difference.
When you're using HTTPS this means that your web server
has a digital certificate installed
and you're going to be using a secure
and encrypted tunnel between your web browser
and that web server that you're connecting to
by using the HTTPS protocol over Port 443.
Now, when it comes to a web server,
this is really any type of server,
whether it's Windows, Mac, Unix or Linux
that is running a web server piece of software.
Generally, if you're running a Windows server
you're going to be using IIS,
which stands for internet information services,
and this is an extensible web server software
that's created by Microsoft for use
with the different families, such as HTTP, HGTP/2 and HTTPS
when you're running a web server.
On the other hand, if you're using a Unix,
Linux, Mac or even a Windows system,
you can use an open source piece of software
known as Apache,
which is by far one of the most popular ways
to run a web server these days.
Now, in addition to running Apache
you can also choose to use NGINX instead.
Now, NGINX which is spelled N, G, I, N, X
is actually a reverse proxy,
a load balancer, a mail proxy, and an HTTP cache
and this gives you better performance and speed
than using something like IIS or Apache
because NGINX has been developed for speed at its core.
Now, when it comes to using HTTP
you're going to be serving up your webpages
using things like HTML,
CSS,
and JavaScript
to be able to display your page
from that web server to the client.
For example, if you go to my website at diontraining.com
you're going to receive back a bunch of HTML,
CSS and JavaScript,
and that way your browser knows
how to display the content that we want you to see.
You do this by going to our website
and issuing a Get-Command,
this is done for you automatically
when you go to your browser and type in
diotraining.com and hit Enter
because it's going to send over a get message
to our web server over Port 80, or Port 443
depending on if you come to me
in an unencrypted or encrypted tunnel,
and then our web server is going to send you back
all of our code so that your browser
can then build our website and display it to you.
Now, when you're going to a web server
to be able to access information,
you're going to do this using a fully qualified
domain name known as an FQDN.
Now fully qualified domain names
are not considered to be case sensitive
so they can be all uppercase,
all lowercase or a mixture of them.
But what makes a fully qualified domain name
is the fact that it has something dot domain dot
and then a top level domain such as com.
So if you go to diontraining.com,
that's technically not a fully qualified domain name
but if you go to www.diontraining.com
that is considered a fully qualified domain name
because that WWW is specifying that you want our web server
instead of something like our mail server
which is located at mail.diontraining.com.
Now, to be able to access
all these different names and addresses,
we have something known as a URL
which is a uniform resource locator.
Now everything on the internet has a URL associated with it
and a URL combines that fully qualified domain name
with a protocol at the beginning.
For example, if you go to https://www.diontraining.com
this tells you that you want to access diontraining.com
which is a website located at www using the HTTPS protocol
over Port 443 to create a secure encrypted tunnel.
And so, as you can see there's really three big pieces
that you have inside of a URL.
You have the protocol,
you have the server that you want to specify
and then you have the domain name.
And when you put all those together
you're going to get something like https://diontraining.com.
The final thing we need to discuss
when it comes to web servers
is this idea of a secure website.
Now, when you go to diontraining.com or www.diontraining.com
it's actually going to forward you over and redirect you
to our secure website, which operates over Port 443.
This is because our secure website has a digital certificate
installed from a trusted certificate authority.
This means that when your web browser connects to my server
it's going to be able to see that we have
that digital certificate installed.
Your system will then be able to create a random code
and it's going to send it over
using my digital certificate and encrypting it,
and when my server receives that it decrypts that
and then we use that number that you sent us
to be able to create a tunnel between your system and mine
where we can transfer information
and nobody else can see it.
That is the benefit of having this encrypted tunnel set up
using Port 443 and using this digital certificate
from my web server to your browser.
So, whenever you're going to a new website
you always want to look for that little lock logo
to make sure you are on a secure site
that is trusted by your browser
because this means anything you type
will only be seen by you
and the site that you're sending that information to
which means you're much more secure
than if you're doing things
in an unencrypted manner over Port 80.