METROVILLE COMMUNITY SCHOOL
LEVEL - 5
Chapter: 01
Computer Networking and Internet
What is a network?
What is Computer Networking?
Computer networking refers to interconnected computing devices
that can exchange data and share resources with each other. These
networked devices use a system of rules, called communications
protocols, to transmit information over physical or wireless
technologies.
Types of Networks:
1. PAN (Personal Area Network)
2. LAN (Local Area Network)
3. MAN (Metropolitan Area Network)
4. WAN (Wide Area Network)
PAN (Personal Area Network):
A personal area network (PAN) is a network that connects electronic devices within a short
range around a single person. PANs are typically wireless and low-power, and they can be
used to transfer data, voice, or audio between devices. Here are some examples of personal
area networks:
● Bluetooth connection between a smartphone and a wireless headset
● Wireless connection between a laptop and a mouse or keyboard
● Connection between a fitness tracker and a smartphone
● Connection between a smartwatch and a smartphone
● Connection between a gaming console and a wireless controller
LAN (Local Area Network):
Local area networks (LANs) are groups of computers and other devices that are connected
together within a limited geographical area, typically a home, school, office building or
campus. Here are some examples of local area networks:
Home Wi-Fi network: This is a common type of LAN that allows devices like computers,
laptops, smartphones, tablets, and smart speakers to connect to the internet and share
resources like printers and files.
Small office network: A small business might have a LAN that connects all the
computers in the office together. This allows employees to share files, printers, and other
resources.
School computer lab: A school computer lab is another example of a LAN. The
computers in the lab are all connected together so that students can share files and resources.
MAN (Metropolitan Area Network):
Metropolitan Area Networks (MANs) cover a larger geographical area than Local Area
Networks (LANs) but smaller than Wide Area Networks (WANs). They typically span a city
or a metropolitan area and offer high-speed data transfer rates to its users. Here are some
examples of Metropolitan Area Networks:
● Campus Area Network (CAN):A CAN connects buildings within a close proximity,
like a university campus, corporate headquarters, or a hospital complex. It can be a
part of a larger MAN or function independently.
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Campus Area Network
● Healthcare Information System:Hospitals and clinics spread across a city can be
linked through a MAN to facilitate sharing of patient data, medical records, and
administrative information.
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Healthcare Information System
● Smart City Infrastructure Network:A smart city network connects various sensors,
cameras, traffic lights, and other devices spread throughout the city for centralized
monitoring and management. This network plays a crucial role in optimizing traffic
flow, improving public safety, and enhancing overall city operations.
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Smart City Infrastructure Network
● Government Communication Network:Government agencies within a metropolitan
area can leverage a MAN for secure and high-speed communication, sharing of data,
and collaboration between departments.
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www.ogcio.gov.hk
Government Communication Network
● Citywide Wi-Fi Network:Many cities offer public Wi-Fi hotspots that residents and
visitors can use to connect to the internet. The infrastructure behind these hotspots is
often a MAN enabling a large coverage area.
WAN (Wide Area Network):
Wide Area Networks (WANs) span vast geographical distances, connecting users, devices
and computer networks across continents. Here are some examples of WANs:
● The Internet:The most recognizable WAN is the internet. It's a global network of
interconnected networks that allows communication and data exchange between
billions of devices around the world.
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Internet WAN
● Corporate WANs:Large companies with geographically dispersed offices and
branches use WANs to connect their local area networks (LANs) together. This
allows employees to share resources, collaborate on projects, and access company
data regardless of their location.
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Corporate WANs
● Virtual Private Networks (VPNs):VPNs create a secure tunnel over the internet,
allowing users to connect to a private network remotely. This is commonly used by
businesses to provide secure remote access to employees or by individuals to access
geo-restricted content.
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Virtual Private Networks
● Bank Networks:Banks typically have a WAN that connects all their branches and
ATMs. This allows them to process transactions, verify accounts, and transfer funds
securely across different locations.
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Bank Networks WAN
● Airline Reservation Systems:Airline reservation systems are WANs that connect
airlines, travel agencies, and other entities involved in air travel. This allows them to
check seat availability, book flights, and manage passenger information in real-time.
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oneclickitconsultancy.medium.com
Airline Reservation Systems WAN
World Wide Web (WWW): This is the part of the internet most people experience.
It's a system of interlinked web pages you access using a web browser. Websites
can contain text, images, videos, and interactive elements.
Online and Offline:
Online refers to being connected and able to access and share information over the
internet. This applies to computers, smartphones, tablets, and even people. You can
say a website is online if it's accessible on the internet, or that your phone is online if
it has an internet connection.
Offline means a device or person is not connected to a network. So a computer
without wifi or a phone in airplane mode would be considered offline. You might also
use offline to describe things you can do without an internet connection, like playing
a downloaded game or reading a book you already have.
URL:
URL stands for Uniform Resource Locator. It's basically an address that tells your
computer how to find a specific resource on the internet, like a website, image, or
video.
Think of it like a house address in the real world. The URL gives your computer all
the information it needs to locate the exact resource you're looking for online.
Hyperlink:
A hyperlink, also often called just a link, is like a digital shortcut you can click on to
be taken to another piece of information online.
Uploading and Downloading:
Uploading and downloading are two sides of the same coin when it comes to
transferring data online. Here's a quick breakdown:
● Uploading is sending data from your device to the internet. Imagine it like
putting things on a shelf. This could be anything from sharing photos on social
media to sending an email with an attachment.
● Downloading is receiving data from the internet onto your device. Think of it
like taking things off a shelf. This could be anything from opening a website
(downloading the webpage content) to saving a music file or movie.
Here's an analogy to make it even clearer:
● Uploading is like mailing a letter - you're sending information out.
● Downloading is like receiving a package - you're getting information delivered
to you.
Browser
Software used to navigate the Internet. Google Chrome, Firefox, Netscape Navigator
and Microsoft Internet Explorer are today's most popular browsers for accessing the
World Wide Web.
Email
Electronic mail; messages, including memos or letters, sent electronically between
networked computers that may be across the office or around the world.
HTML
Hypertext Markup Language, a standard of text markup conventions used for
documents on the World Wide Web. Browsers interpret the codes to give the text
structure and formatting (such as bold, blue, or italic).
HTTP
Hypertext Transfer Protocol, a common system used to request and send HTML
documents on the World Wide Web. It is the first portion of all URL addresses on the
World Wide Web.
Excel – 2013
Red Color – instruction
Blue Color – Actual Formula
1. Addition formula for large amount of data:
=SUM(select the area where the data is) than
press enter
2. Percentage: Obtained marks x 100 / Total Marks
3. Grading formula: =if(% cell select>=90,”A++”, if(%
cell select>=80,”A+”, if(% cell select>=70,”A”, if(%
cell select>=65,”B+”, if(% cell select>=60,”B”, if(%
cell select>=50,”C”, if(% cell select>=40,”D”, if(%
cell select<40,”F”))))))))
4. Count formula: =Countif(select the area,”what
ever you want to count”)
5. Duration Formula: =datedif(starting date, present
date,”D” for Days, “M” for month, “Y” for year )
6. Vlookup formula: =vlookup(lookup value,table
array,col_index_num,rang_lookup)
