CHAPTER 10
COMMUNICATION
What is Email?
Email (Electronic Mail) is one of the most fundamental ICT
applications used globally for quick, asynchronous
communication (meaning the sender and receiver don't have
to be online at the same time).
Understanding CC and BCC (The Copying
Game)
These features are essential for managing who
receives an email and who knows about it.
•Carbon Copy (CC): Used when you want to send a
copy to someone who needs to be informed, but is not
the main recipient.
Example: You email your teacher (To) but CC your
parent so they know you sent it. Everyone can see the
CC list.
•Blind Carbon Copy (BCC): Used when you want to
send a copy to someone secretly. The primary
recipients (TO and CC) will not see the names of
people listed in the BCC field.
Example: You send an email update to 50 customers
(To). You BCC your manager so they have a copy,
but none of the 50 customers know the manager
received it. This is useful for protecting privacy.
Constraints and Guidelines (Netiquette)
Using email effectively requires following
guidelines, often referred to as Netiquette
(Internet etiquette).
1. Acceptable Language and Tone:
•Always be polite and professional, especially in a
work or school environment.
•Avoid using ALL CAPS, as this is interpreted as
shouting.
•Use clear subject lines so recipients know what
the email is about immediately.
2. Security and Confidentiality:
•Do not send sensitive personal identifiable
data (like passwords or bank details) via
unsecured email.
•Be careful when opening attachments from
unknown senders, as they could contain
malware or viruses.
3. Employer Guidelines:
•If you work for a company, they often have rules about email
usage, such as not using work email for personal matters or
avoiding large attachments that clog up the network.
The Problem of Spam Email
Spam refers to unsolicited (unwanted) bulk electronic
messages, usually commercial in nature.
Characteristics and Effects of Spam:
•Often contains dubious or fraudulent content (scams).
•Wastes bandwidth and storage space.
•Wastes user time sorting and deleting messages.
•Can slow down network performance.
Methods to Help Prevent Spam:
•Use spam filters (software that checks emails
and moves suspicious ones to a separate
folder).
•Do not publish your primary email address
widely online.
•Never reply to spam emails, as this confirms
your address is active.
•Use a secondary, disposable email address
for signing up to online services.
The Internet:
This is the vast, global network of interconnected computer
networks. It is the physical infrastructure (cables, routers,
servers).
Analogy: The entire network of roads, railways, and telephone
lines covering the whole world.
.
2. World Wide Web (WWW):
This is the collection of documents and resources (web
pages, images, videos) that are accessible via the
Internet using HyperText Transfer Protocol (HTTP).
The WWW is only one part of the Internet (other parts
include email and FTP).
Analogy: The traffic (cars, lorries, buses) that travel on
the global road network.
HTTP & HTTPS
What is HTTP & HTTPS?
What is HTTP?
HTTP is an application-layer protocol designed for
transferring hypertext documents such as HTML, images,
videos, JSON, CSS, and more. HTTP follows a stateless,
request-response model. This means every request from a
browser to a server is independent and does not retain
session history.
•Hypertext Transfer Protocol (HTTP) allows communication
between clients and servers for website viewing
•HTTP allows clients to receive data from the sever
(fetching a webpage) and send data to the server
(submitting a form, uploading a file)
•HTTPS works in the same way as HTTP but with an
added layer of security. All data sent and received using
HTTPS is encrypted
•HTTPS is used to protect sensitive information such as
passwords, financial information and personal data
FTP
What is FTP?
•File Transfer Protocol (FTP) allows sending and
receiving files between computers
•Uploading and downloading files to/from a web server
is often completed using FTP
•FTP offers greater efficiency and support for bulk
transfers and large files such as resuming interrupted
transfers
•FTP clients are software applications that use the FTP
protocol to make the process easier for users
SSL & TLS
What is SSL & TLS?
•Secure socket layer (SSL) is a security protocol developed to
provide secure communication over the internet
•TLS is a successor to SSL and is also a security protocol used to
provide secure communication over the internet
•They both use a combination of symmetric and asymmetric
encryption to secure data and ensure data integrity
•SSL operates by encrypting a user's data using a public key
• This is done by sending a digital certificate to the user’s browser
• This contains the public key which can be used for authentication
3. Intranet:
Intranet
An Intranet is a private network designed exclusively for an
organization's internal use. It operates within a closed
environment, typically using Local Area Network (LAN)
infrastructure, where each computer has a unique MAC address
for identification and location purposes.
Intranets enable employees to share documents, manage
calendars, collaborate on projects, and access internal resources
securely. The network runs in a client/server environment and
restricts access to authorized personnel only. While an intranet
may connect to the Internet, it requires robust security
measures to prevent unauthorized external access.
4. Extranet:
A private network that extends an intranet to
allow controlled access by specific external
users (like suppliers or trusted customers).
Example: A car manufacturer allowing their
tire supplier to log in and check current stock
levels.
Common Online Tools (Web Applications)
•Blog (Web Log): An online journal or diary, usually run by an
individual or small group, featuring regular entries (posts). Uses
include personal commentary or marketing.
•Forum: An online discussion site where people can hold
conversations in the form of posted messages (threads). Uses
include technical support or community interaction.
•Wiki: A website that allows collaborative editing of its content and
structure by its users. The most famous example is Wikipedia.
•Social Networking: Platforms that allow users to build public or
semi-public profiles and connect with others (e.g., sharing photos,
status updates).
Internet Functionality and Structure
Core Components:
•Internet Service Provider (ISP): The company that provides you with
access to the Internet (e.g., your phone company or broadband
provider).
•Web Browser: The software application used to view and navigate the
WWW (e.g., Chrome, Firefox).
•Uniform Resource Locator (URL): The full address used to locate a
resource on the web, including the protocol (like HTTP) and the domain
name.
Example: https://www.example.com/page.html
•Hyperlink: An element (text or image) in a document that, when
clicked, jumps to another document or web resource.
Finding and Evaluating Information
Using Search Engines
A search engine is an essential tool for navigating the vastness of the
internet.
Advantages and disadvantages of using search engines often relate
to:
•Speed of searching: Usually very fast.
•Amount of information: Provides massive quantities of data
(Advantage).
•Speed of finding relevant information: Can be difficult, as filters
and keywords must be precise (Disadvantage).
•Ease of finding reliable information: Highly variable. Many results
may be untrustworthy (Disadvantage).
valuating Information Reliability
You must critically assess the information you find online.
Ask these four key questions (Remember: URBV):
1. Up to date: When was the page last updated? Is the
information still current? (Crucial for things like medical
advice or scientific data.)
2. Reliable: Is the source trustworthy? Is it a university, a
government body, or a known expert? Avoid anonymous
sources.
3. Biased: Does the source have a reason to show only
one side of an argument? (e.g., a company reviewing its
own product will be biased).
4. Valid: Can the information be checked against other
Internet Protocols and Security
Key Protocols:
Protocols are the rules governing how data is transmitted.
•HyperText Transfer Protocol (HTTP): The fundamental protocol used to transmit web pages over the
internet.
•HyperText Transfer Protocol Secure (HTTPS): The secure version of HTTP. It uses SSL (Secure
Socket Layer) or TLS to encrypt the data transmitted between the web server and your browser.
If you see HTTPS, it means your connection is encrypted and more secure (e.g., for online shopping or
banking).
•File Transfer Protocol (FTP): A standard protocol used to transfer files from one computer to another
over the internet (often used for uploading websites to a server).
•Secure Socket Layer (SSL): A layer of encryption technology that creates an encrypted link between a
server and a client (your web browser). This is what makes HTTPS secure.
Risks and Restriction Methods
Using the internet carries risks, particularly exposure to
inappropriate or criminal material.
Methods for restricting access and protecting children:
•Parental Control Software: Software installed on a
home computer that filters content, blocks specific sites,
or limits screen time.
•Educational Filters: Networks in schools or libraries
often use filtering software to block content deemed
unsuitable for students, enforcing Acceptable Use
Policies.
•ISP Control: Internet Service Providers (ISPs) often offer
family safety settings or controls that filter inappropriate
content at the network level before it even reaches the
home router.