ICT

Introduction to computer networks

len Alfred Ajibola - Wed, 17th July, 2019 @ 4:44 PM

Topics in ICT

Introduction to routers in networking Wired router and wireless router explained What are core routers in networking? Virtual routers explained with its configuration Edge router explained with its types Domain Name System explained Types of computer network Functions of a router Computer scheme of work, SS1, First Term Computer scheme of work, SS1, Second Term Computer scheme of work, SS1, Third Term Introduction to computer networks Types of DNS server Open Systems Interconnect: Layers of the OSI Model Internet of Things (IoT), How IoT works, its advantages and challenges How to consume less data on android phone Best programming languages to learn The internet and world wide web explained Computer Hardware, Parts and Functions of Computer Hardware


Academic Questions in ICT

Please click here to see all Questions and Answers

DNS belongs to layer _____ of the Open System Interconnect (OSI) model of networking.

  • A. One

  • B. Two

  • C. Three

  • D. Four

  • E. Five

  • F. Six

  • G. Seven

Which of the following DNS servers receive queries directly from computers, phones and other client devices?

  • A. Root Nameserver

  • B. Top Level Domain (TLD) Nameserver

  • C. Bottom Level Domain (BLD) Nameserver

  • D. Authoritative Nameserver

  • E. Direct Nameserver

  • F. Recursive DNS Server

The uppermost layer of the Open System Interconnect (OSI) model of networking is the _____ layer.

  • A. Physical

  • B. Application

  • C. Network

  • D. Transport

  • E. Data Link

  • F. Presentation

Concerning the internet of things, which of the following statement is incorrect?

  • A. Humans will become connected to the internet through the internet of things

  • B. It refers to the billions of physical devices that will be connected to the internet

  • C. Big data is associated with the internet of things

  • D. Presently, we have more humans living on earth that things connected to the internet

  • E. China, North America and Europe accounts for over two thirds of internet connected things

  • F. The ultimate goal of the Internet of things will be made a reality through IPv6

What is the first step towards disabling automatic image download on WhatsApp?

  • A. Click on the three dots on the top right hand corner

  • B. Click on the WhatsApp logo

  • C. Click on the settings icon on the top right corner

  • D. Click on the settings icon located on the to top-center of the app

  • E. Click directly on the storage and data icon located on the top right corner

  • F. Click on the mobile data usage icon located on the top right corner

The followings are ways to conserve data on android phones except _____.

  • A. Turning on data saving mode

  • B. Activating background apps

  • C. Use of Wi-Fi to update apps

  • D. Disable automatic image download on WhatsApp

  • E. Watch low resolution videos on youtube

  • F. Utilizing a reputable data saving app on google playstore

Twitter was launched in _____.

  • A. 2003

  • B. 2004

  • C. 2005

  • D. 2006

  • E. 2007

  • F. 2008

Due to the limitation of the Internet Protocol version 4 address, _____ was created.

  • A. IPv5

  • B. IPv6

  • C. IPv7

  • D. IPv8

  • E. IPv9

  • F. IPv10



What are Computer Networks?

We live in a digital age where computers are at the core of almost everything. Gone were the days when people were always compelled to visit a shopping mall in order to purchase their needs and wants.

Although people may still visit the supermarket to buy their needs, however, the emergence of computer networks have transformed a wide range of commercial activities. As an instance, you can purchase any car of your choice from any part of the world in the comfort of your home; all thanks to computer networks.

Please read on the meaning, scopes, functions and characteristics of commerce here.


Computer network is simply a group of computers that are linked to each other such that they can share resources.

Generally, these groups of computers that form a network are called nodes.


Some of these nodes will function to store information which will be served to other computers. The nodes that function to store and serve such information are known as servers.

Conversely, some of the nodes will request information from the server. The computers that act in this manner are termed as clients.


It is important to state that a computer isn't just a laptop or PC (personal computer). Phones and smart watches are computers too. Other devices that can also act as computers include television, cars, buses, refrigerator, doors, fans, clothes and so on. Understand that we are fast approaching the new era of networking; that is, the 'internet of things'.

Please read more on the internet of things here.


Before we look into the types of computer networks, the analogy below will help you better understand what computer networks are.

  • You are reading this article from a computer device which could be a phone or PC.

    Your computer device will need to be connected to some form of network before you can have access to the internet.

    Over the internet are so many other computers that have lots of information stored on them. These are called servers.

    As you might have guessed, your phone or computer on which you are reading this article is a client machine. It required a form of network (computer network) to get this stored information from another computer called the server which resides over the internet.

    The point is: there must be a form of network through which data is transferred back and forth between the client and the server.

    Please read on the OSI model of networking here.


In another example, you can create a simple network between two phones through the use of bluetooth, wireless connection or infrared. Once this basic network is created, you can share images, videos and other files between both computers. This simple network created by you is also a computer network.

 

Types of Computer Networks

Computer network can be categorized based on the followings:

  • Geographical size

  • Design

Below are types of computer networks based on geographical size:

  1. Personal Area Network (PAN)

  2. Local Area Network (LAN)

  3. Campus Area Network (CAN)

  4. Metropolitan Area Network (MAN)

  5. Wide Area Network (WAN)

Please read the types of network based on geographical size here.


The two main form of networks based on designs are:

  1. Client and Server Network

  2. Peer to Peer Network

Kindly share this article via the links below:


len


Please click here to contact Alfred if you require any of the following services:

  • If you need a standard website at an affordable price.

  • Online training on the academic subjects: biology, chemistry and basic science.

  • If you require an advanced smart school management system (web application) for your school.

Click here to read on Len Academy Smart School Software.


Please click here to follow Len Academy on Google News.



Amazing facts in ICT

1,000 computers are used to retrieve the answers to your Google search (query) in 0.2 seconds

The first hand-held mobile phone call was made in New York City on April 3rd, 1973

The logo for gmail was designed the night before it was launched

Coca Cola owns all the domain names (website names) that can be read as ahh. They include: ahh.com, ahhh.com, ahhhh.com, ahhhhh.com, ahhhhhh.com and so on..., all the way up to 62 'h's!

YouTube is a video-sharing platform which commenced operations on February 14, 2005 (Valentine's day). Three former PayPal employees -> Chad Hurley, Steve Chen and Jawed Karim created the YouTube service (as a dating app) until Google bought it in November 2006 for US$1.65 billion

Smoking near a Mac device - Len Academy

Smoking near an Apple (Mac) computer voids the warranty.

When you add /4 to the end of Facebook's URL, it will take you to Mark Zuckerberg.

You can try it on you own; or better still, try the link below:

facebook.com/4

Apple iPad retina - Len Academy

Apple iPad retina display is actually manufactured by Samsung

The big five tech companies of the world as at 2018 are :

Google

Apple

Facebook

Amazon

Microsoft


Notable points in ICT

Python is one of the most popular programming languages, and will still remain relevant for a long time.

Python can be used for almost every kind of project including web application, machine learning, mobile and desktop applications, networking servers, APIs, scrapers, application’s backend and so on.

There is a great availability of third-party libraries for the python language. For this reason, it becomes one one of the easiest languages to learn as a beginner.

Believe it or not, Hypertext Preprocessor (PHP) still remains one of the most popular backend language for web applications, even though it is currently facing a stiff competition from python language.

Content Management Systems (CMS) like wordpress and drupal are written in PHP for its backend. Interestingly, some of facebook’s backend were also written in PHP.

As at 2019, the backend of more than 40% of active websites are powered with PHP. In fact, Len Academy is also powered by PHP for its backend.

If you wish to manipulate databases via Structured Query Language (SQL) with a programming language that has dynamic capabilities, then PHP is your language of choice.

Please read on the best programming languages to lean here

Below are notable dates on internet evolution:

  • 1983: The Domain Name System (DNS) created the '.com .edu .gov .org and .net' systems for naming websites

  • 1985: The first registered domain name - 'symbolics.com' came into existence

  • 1992: The first audio and video were uploaded over the internet

  • 1992: The phrase 'surfing the Internet' became popular

  • 1993: The number of websites reached 600

  • 1993: White House and United Nations go online

  • 1994: Microsoft creates a Web browser for Windows 95

  • 1994: Yahoo! is created by Jerry Yang and David Filo

  • 1995 Amazon and eBay were launched online

  • 1996: 'The Dancing Baby' becomes the first viral internet video

  • 1997: Netflix is founded by Reed Hastings and Marc Randolph

  • 1998: Google search engine came into existence

  • 2003: The worm 'SQL Slammer' spread over the internet within 10 minutes

  • 2004: Facebook goes online

Please read more notable dates on internet evolution here

Computer hardware is the collection of physical parts of a computer system.

Physical parts of a computer are those parts that you can see and touch. It may also be referred to as the 'equipment of the computer'.

When the computer case is opened (with a screwdriver), one would see the different hardware components inside of it. It's important to state that some other hardware components are present outside the computer case; and these are termed peripherals.

Below are hardware components seen inside the computer case:

  • Motherboard

  • Central Processing Unit (CPU)

  • Graphics Processing Unit (GPU)

  • Power supply Unit (PSU)

  • Northbridge

  • Southbridge

  • Peripheral Component Interconnect (PCI) slots

  • Network Interface Card (NIC)

  • Random Access Memory (RAM)

  • Ventilation fans

  • Heat sink

  • Hard Disc Drive (external present)
  • Solid State Drive (SSD)

  • CMOS battery

  • Optical Disc Drives (external present)

  • USB port, PS2 port, Ethernet port and other ports

  • Expansion Ports / Slots

Please read more on computer hardware here

Hardware components seen outside the computer case are called peripherals. The peripherals are grouped into the following:

  1. Input devices: They provide information to the computer.

  2. Output devices: Brings out information from the computer.

  3. Storage devices: They store information or data.

Below are examples of some peripherals:

  • Keyboard (input)

  • Monitor (output)

  • Mouse (input)

  • Webcam (input)

  • Touch Pad (input)

  • Universal Serial Bus (USB) flash drive or memory card (storage)

  • Hard disc drive (storage)

  • Stylus (input)

  • Joystick(input)

  • Printer (output)

  • Speaker (output)

  • Headphones (output)