Internet, is network of computers,
from outside it looks very complex but internally it works on few simple principles.
Here principles I mean standards/protocols like HTTP, TCP/IP, html and also laws
of electromagnetism
(in simple, its law of light. it’s very important for internet, because all of
the data will be travelling near to speed of light otherwise internet will be very
slow. Trick here is whatever web request or response will be converted into binaries
and send them via wave pattern inside optic cables)
Before I explain components
of web. I just like to mention how standards or protocols helps to develop such
complex systems. Standards like HTTP is nothing but a few set of rules on which
two system will interact seamlessly because both the system know what is the rules/standard/language.
For ex: when traffic signal light is red we stop, green go. Same way web
browser and web server both have knowledge about HTTP and its language.
So basically when you click
on a link on web browser, it talks to a remote web server and gets back the data
what you have asked for and displays it on browser.
Following are the key
components of the web, together they make internet work. Each one of them is
big enough to accommodate a book or more. So I will try to explain each one briefly
and hope easy to understand. Actually there are lot more components like DNS,
OSI models, Firewall, and others involved in to make internet work but for us
to understand how web works below items are good enough.
HTTP,
Transport Layer (TCP/IP), Web Server, ISP, Browser, HTML5 (structure),
CSS3
(presentation), JavaScript (interactivity)
Browser:
First thing first, browser is a
software/window to internet through which user browse the web. How can it talk
to remote server, get data like text, picture, video, and display? Answer is
HTTP, html … Browser is a software/program built on standards/protocols like
http, html, css, javascript. For ex: when browser sees content like make me
bold it render/display like “make
me bold”, so it’s nothing rocket science. All the standards or rules of
http, html… are already coded inside software to how to display text, make
calls remote server, etc.
HTML, CSS, JavaScript: these
are language of web. HTML is for structuring the data, CSS to present the data
and JavaScript for interaction or behavior. Just html is enough for to display
data but it will very dull and boring. To give life to web CSS, JS came to
existence. When Tim (legend) invented the web he just thought to link the
documents and access it over network (I am simplifying itJ).
He had no idea one day web will explode so big like what we see today.
HTTP: hypertext transport protocol, is an application protocol.
Web browser/client sends http request to web server and web server returns http
response and content as html. HTTP has specified different way to request and
response. Here are the http methods : HEAD, GET, POST, PUT, DELETE, TRACE … don’t
worry if you don’t get it, these are verbs or actions clients request to server
for ex: HEAD means header of http request/response, GET means get a resource
from web server, POST means get or create a list of resource in the server. So
this is how server know how to respond if any request comes from client.
TCP/IP: Transporting of
http bundle to web server involves lot of behind the scene actors like OSI
models ( its seven layer of network, it
defines how data will travel from your computer to Ethernet to cable to
computer next to you or other side of the world). But in that layer TCP/IP is
important for us to understand how http request will be get pocketed,
addressed, transported and received. This
layer is very important because activities like 3 way handshake and other
connection establishment all this will happen less then fraction of second. (Thanks
to speed of lightJ)
ISP: is network of thousands of miles fiber optic cable,
spread across intercontinental or via satellite. Its organization provides
internet access. Through which all your web request and response will travel.
Web Server:
As name says its serve the web request. The server is just a software not the computer.
Like web browser, server is also a program coded to understand HTTP methods and
respond accordingly to http request. Basically server will respond with
documents, images, videos, etc. Web server may be right next door or across
ocean.
Summary:
Web/internet is very exciting place. Its part and parcel of our life now. Its
topic of worth many books, but I just thought briefly dot the maps and present
brief idea about web to users. I might have missed to explain few points or
explain in more detail, it’s just because to simplify. Thanks!
