Networking and Internet
About Network
Computer Networking refers to the interconnection between the different types of computing devices that exchange data and resources with each other. So basically The deices which are connected with other devices through wires or wireless that create Network.
About Internet
So The Large group / connection of networks / global Networks that is Internet. In Internet Whole World Computers are connected with each other and exchange data and resources files.
it is called networks of network .
the wires which are kept inside oceans and seas , that is internet which connected whole world computers .
Uses Of Internet
Learning
Banking
Email Sending and receiving
Chatting
playing games
Streaming Videos and many more
We cannot think today's world without Internet . It is basic needs of people nowadays.
How Devices are Connected on Internet ?
The devices are connected through wires and cables . Computers + Wires + protocols = Internet.
Some terms:
sender : the sender is called client who sends request like get, post, put, delete..
receiver : the receiver is called server who sends response of the request by client...
data : the data is send between them which is named as Payload.
Address : the devices has given address which is connected on internet which is called IP.
large data are converted into small pieces of data called packets.
Bandwidth
The maximum amount of data that can be sent per second over network connection called bandwidth.
it is measure in bits per second like mbps , gbps ...
Water Pipe Analogy :
pipe Width : Bandwidth
water : data
How much water reaches you : download speed -
Thick Pipe = more water per second
thin Pipe = less water per second
Bandwidth is about capacity not about speed.
for example : 1. big truck on highway (high bandwidth) 2. motorcycle in empty road (less bandwidth less latency )
Latency (Time Delay)
measured in ms.
apply in : online games , video calls
Download and Upload Bandwidth
Download Bandwidth : using in watching videos, browsing websites etc.
Upload Bandwidth : sending emails, files sharing , uploading photos etc.
Why Developer Care about Bandwidth ?
Compress Image
reduces files size (code size)
use caching
send needed data only
effects:
slow website
bad user experience
high server cost
example:
Sending 5MB image vs optimized 200KB image = BIG difference.
Bandwidth vs Throughput
Bandwidth : maximum possible capacity of data flow per sec.
Throughput: actual data received.
Some Terms
congestion : Too many users -> traffic jam -> slow net
Throttling :intentionally slowing down your internet speed by the network provider or server.
jitter :unstable delay eg: bad video calls.
packet loss : some packets might lost so TCP needs to send request which makes slower the website.
What is WWW and WWW ≠= Internet ?
Internet is global network . it is network of network in which many services are running like
email service
file transfer
online gaming
video streaming
websites browsing
but WWW is a one service or part of internet that is web browsing. It is collection of websites which
are stored on web servers and connected to local computers through Internet.
These website includes text pages , images , videos , audios.
Users can access these sites from any part of world through internet using devices computers, laptops , smart phones etc.
Analogy:
Internet is like Road and WWW is the vehicle on road.
for Example : people say my internet is not working : it means website is not loading .
like WhatsApp open but website not open it means WWW is down NOT Internet .
