servers browsers vII

Let's talk about browsers and servers.

This video will teach you
about their purpose

and how they contribute to the giant
network that we know as the Internet.

What happens when you request
a website in your browser?

Well, every time you type
a web address and press Enter,

a series of things happen
in the few seconds

it takes for the website
to appear on your screen.

Over recent decades
there have been many web browsers.

Some of the most popular today
are Chrome, Firefox, Safari,

Internet Explorer, and Opera.

All of these browsers serve the same basic
purpose to display websites for you

to read and interact with.

But just how do they do this?

First, the browser takes
the web address you provided

and sends a request
to a server across the Internet

for the files that make up the website.

The contacted server is dedicated
to hold the website's files.

It may even be thousands of miles
away from you and your device.

Once a server receives the request,

it contains logic
for processing the request

and identifying the files and data
that the client has specified.

It responds to the browser's
request with the necessary files.

This is a process that allows the browser
to display website files to you

and it happens in a few seconds
it takes for websites

to load on your device screen.

You may be asking yourself
what is a server?

A server is a specialized computer
connected to a network.

The role of this computer is to listen
for requests from network devices

and send back data.

Servers provide or serve up
resources like website files, data,

and assets like images or videos
along with other cool things.

Servers are not like the computers
you may be used to.

They are focused
on data storage and retrieval

so they have no monitors or keyboards.

A server will need lots of computing power

to serve up websites that reach
thousands or even millions of users.

Next, we need to understand

how the browsers and servers
understand each other.

The Internet follows protocols or rules

that govern the format of data
sent over the Internet or other networks,

Browsers and servers
communicate with one another

using the Internet protocol known as HTTP.

You've seen this before.

HTTP, or hypertext transfer
protocol, allows for data transfer.

When you see the 's' at the end of HTTP
the data is being transferred securely.

An important part of the hypertext
transfer protocol is that each request

has a request method that specifies
the type of request being made.

For example, if the user
is just asking to fetch a resource

this is specified as a GET request.

If a user is sending data
to the server, for example,

such as submitting information via form
this is specified as a POST request.

When the server sends back a response

it sends a status code that accompanies
the requested resource.

You might be familiar
with scene 404 error messages

when browsing the Internet.

This is an HTTP response code

that indicates that the requested
content wasn't found.

HTTP provides a reliable structure

to the interplay between
the client and the server.

Let's review what we learned today.

There are three important
things to remember.

One, the browser sends
requests to the server

and displays or renders website files.

Two, the server stores website files

and sends them to the web
browser upon a request.

Three, HTTP, or hypertext transfer
protocol, is a standardized set of rules

for how browsers and servers
transfer data to one another