in this lesson we're going to start at the very beginning and provide formal definitions for what
is ssl and what is tls here is the internet the internet is often depicted as this cloud
illustration but inside the internet is actually just a bunch of different routers that are handing
data off to one another on either side of the internet is you and who you are speaking to
all of these routers are owned by different isps which stands for internet service provider these
isps are in charge of maintaining these routers which are going to hand data off to one another
so when you are trying to speak to something on the other side of the internet you are putting
data on the wire which is then going to be handed off from router to router owned by different isps
all the way across the internet before it arrives to the other side the point that i'm trying to
make is as soon as you put data on the wire you no longer have control over what happens to that data
that data is literally in the hands of all these different isps as it's passing across the internet
now most commonly on the internet the type of data that is transferred is websites
meaning this server could be the web server in charge of hosting the site site.com but what
exactly is a website well a website is something written in html which stands for hypertext markup
language and transferred in http which stands for hypertext transfer protocol so for example
this right here is an example of html you'll see an html page is simply text with different
tags and different content that is meant to be displayed by web browser and in order for this
client to receive a copy of this html page it's going to have to send an http request
which will look something like this it's asking for the page index.html from the host site.com
this will prompt the web server to respond with a copy of that html page that html page will then be
handed from router to router across the internet where it'll arrive on the client and the client's
web browser will turn that into something that's a little bit more visually appealing so that is
the definition of a website and an example of html and http an important thing to understand
is that at no point in this process did any sort of encryption happen this was the html page and
this text is literally what was sent across the internet to the other side it might not look like
there's anything too dangerous about anyone in the middle seeing the contents of this particular
http transfer the websites are not always simply displaying information sometimes they are asking
for information like a username or a password or a bank account number or a credit card number
if the user fills in all these fields that'll be sent as is across the internet to the other side
and anyone in the path will have access to what was sent this is why most browsers will display an
error if you start filling in these text boxes that are meant to be transferred in http and
this is actually the problem that ssl and tls are trying to solve what ssl and tls do is they build
a secure protected tunnel across the internet and now with this ssl tunnel the client and the server
can share information safely across the internet what you are looking at here is what's known as
https https is an html webpage transferred using the http protocol secured by an ssl tunnel
but websites are not the only thing that ssl and tls can protect they can also protect any other
data transfer this is known as an ssl vpn the most common use case for an ssl vpn is for a client to
connect to some sort of corporate network the client can build an ssl vpn across the internet
to the corporate firewall and now any corporate resources that the client needs to access
it can access securely through this ssl tunnel for instance corporate email or corporate databases
or files the other common example of an ssl vpn is connecting to a public vpn provider something like
expressvpn or norvpn or cyberghost or a bunch of others these providers allow a client to build an
ssl tunnel to their network and now any internet facing traffic that is sent by this client will go
through this tunnel into the vpn provider's network and then out to the actual internet
what this does is it hides the ip address of the client and potentially makes the
client appear like they're coming from a different location than they really are in
so that is the definition of ssl and tls but there's still something we haven't answered why do
we have two different names for the same function well let's talk about it ssl stands for secure
sockets layer and tls stands for transport layer security ssl is the protocol netscape
created way back in 1994 in order to bring security to the internet then in 1999 the
ietf took over maintenance of the ssl protocol ietf stands for internet engineering task force
and they are responsible for maintaining many of the public internet protocols and when they took
over the ssl protocol they renamed the protocol as tls that is why there are two different terms
one of them is the protocol the netscape created and maintained and the other one is the protocol
maintained by the ietf so you can consider both of these terms as referring to the same protocol
or more accurately as different versions of the same protocol today the world mostly uses the
newer version of the protocol tls but the older term still persists and people still refer to
this as ssl so typically these two terms are used interchangeably but we are actually getting ahead
of ourselves there's actually a few different versions of ssl and a few different versions of
a tls and we're going to be looking at each of those in a later lesson in this module
so with the answer to what is the difference between ssl and tls out of the way we actually
bring this lesson to a close the main takeaways for this lesson is having a clear definition of
what ssl and tls are in that they create a secure protected tunnel across the internet
and understanding the three main use cases of ssl and tls the first being using https to securely
transfer websites and the other two being using an ssl vpn to securely connect to a corporate network
or to connect to a public vpn provider to hide your identity in the next lesson we're going
to be looking at what ssl and tls are doing to actually protect your data that'll give
us a proper definition for what it means to have secure data transfer but that's it for this lesson
i hope you enjoyed this video i want to thank you for watching and i'll see you in the next one
did you enjoy this lesson do you want to understand the rest of the ssl and tls ecosystem
if so you'll want to check out my new course practical tls it's a comprehensive deep dive
into the world of sl and tls designed to make you an sl expert regardless of where you are now
this course is all you need to help you become the next ssl expert on your team
or to help you nail those job interview questions to learn more check out pracnet.net tls or click
the link in the description otherwise thank you for watching and we'll see you in the next video