Central Processing Unit (CPU) consists of the following features − CPU is considered as the brain of the computer. CPU performs all types of data processing operations. It stores data, intermediate results, and instructions (program). It controls the operation of all parts of the computer.

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Dhaka International University
Department of Political Science
Course Name: Basics of Computer
Course No: 0611.1.1.01
Submitted To
Suman Ahmed Saikan
Lecturer
Department of CSE
Dhaka International University-DIU
Batch: 19th& 20th Semester: 2nd
CPU,Malware,Virus,Email,DNS
February 1, 2024

2. CPU
Central Processing Unit (CPU) consists of the
following features −
 CPU is considered as the brain of the computer.
 CPU performs all types of data processing operations.
 It stores data, intermediate results, and instructions (program).
 It controls the operation of all parts of the computer.
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3. CPU
CPU itself has following three components.
 Memory or Storage Unit
 Control Unit
 ALU(Arithmetic Logic Unit)
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4. MEMORY OR STORAGE UNIT
 It stores all the data and the instructions required for
processing.
 It stores intermediate results of processing.
 It stores the final results of processing before these results
are released to an output device.
 All inputs and outputs are transmitted through the main
memory.
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5. CONTROL UNIT
 It is responsible for controlling the transfer of data and
instructions among other units of a computer.
 It manages and coordinates all the units of the computer.
 It obtains the instructions from the memory, interprets
them, and directs the operation of the computer.
 It communicates with Input/Output devices for transfer of
data or results from storage.
 It does not process or store data.
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6. ALU (ARITHMETIC LOGIC UNIT)
Arithmetic Section
Function of arithmetic section is to perform arithmetic operations
like addition, subtraction, multiplication, and division. All
complex operations are done by making repetitive use of the
above operations.
Logic Section
Function of logic section is to perform logic operations such as
comparing, selecting, matching, and merging of data.
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7. DIFFERENCE BETWEEN INTERNET, INTRANET AND
EXTRANET
1. Internet :
The network formed by the co-operative interconnection of millions of
computers, linked together is called Internet. Internet comprises of :
 People : People use and develop the network.
 Resources : A collection of resources that can be reached from those
networks.
 A setup for collaboration : It includes the member of the research and
educational committees worldwide.
2. Intranet :
It is an internal private network built within an organization using
Internet and World Wide Web standards and products that allows
employees of an organization to gain access to corporate information.
3. Extranet :
It is the type of network that allows users from outside to access the
Intranet of an organization.
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8. DIFFERENCE BETWEEN INTERNET, INTRANET AND
EXTRANET
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9. MALICIOUS SOFTWARE(MALWARE)
1. Ransomware
Ransomware is software that uses encryption to disable a target’s
access to its data until a ransom is paid.
Example: RobbinHood
2. Fileless Malware
Fileless malware doesn’t install anything initially, instead, it
makes changes to files that are native to the operating system,
such as PowerShell or WMI.
Example: Astaroth
3. Spyware
Spyware collects information about users’ activities without their
knowledge or consent.
Example: Dark Hotel 9

10. MALICIOUS SOFTWARE(MALWARE)
4. Adware
Serves unwanted advertisements.
Example: Fire Ball
5. Trojan Horse
A Trojan disguises itself as desirable code or software. Once
downloaded by unsuspecting users, the Trojan can take control
of victims’ systems for malicious purposes.
Example: Emotet
6. Worms
Spreads through a network by replicating itself.
Example: Stuxnet
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11. MALICIOUS SOFTWARE(MALWARE)
7. Rootkits
Gives hackers remote control of a victim's device.
Example: Zacinlo
8. Key Loggers
A keylogger is a type of spyware that monitors user activity.
Example: Olympic Vision
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12. VIRUS
Computer virus refers to a program which damages computer
systems and/or destroys or erases data files. A computer
virus is a malicious program that self-replicates by copying
itself to another program.
Symptoms:
 Letter looks like they are falling to the bottom of the screen.
 The computer system becomes slow.
 The size of available free memory reduces.
 The hard disk runs out of space.
 The computer does not boot.
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13. 8 TYPES OF VIRUS
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14. SPREADSHEET SOFTWARE
A spreadsheet is a computer program that can capture, display
and manipulate data arranged in rows and columns.
Example:
1. Microsoft Excel
2. Google Sheets
3. Apple Numbers
4. Zoho Sheet
5. Libre Office
6. Quip
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15. THE EXCEL DOMAIN AND THE ALTERNATIVE
SPREADSHEETS
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16. PRESENTATION SOFTWARE
Presentation software, also known as graphics presentation
applications or presentation graphics programs, is a category of
software used to create content where information is often
represented in a graphical or visual way.
Example:
1. Microsoft PowerPoint
2. Google Slides
3. Prezi
4. Canva
5. Powtoon
6. Keynote
7. Adobe Express 16

17. PRESENTATION SOFTWARE
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18. WORD PROCESSOR SOFTWARE
A word processor is a device or software program capable
of creating, storing, and printing text documents. It allows
users to write and modify text, display it on a screen,
save it electronically, and print it out.
Example:
1. Microsoft Word
2. Google Docs
3. Zoho Docs
4. Libre Office
5. Word Perfect
6. Ragtime
7. Scrivener 18

19. WORD PROCESSOR SOFTWARE
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20. EMAIL
Definition: Electronic mail, commonly shortened to “email,” is a
communication method that uses electronic devices to deliver
messages across computer networks.
An Email consists of four things:-
Username - The first part of an email address is the username. This is the
unique name that you or your ISP select. This can be your real name or
a nickname. Businesses may use themed usernames or their company’s
legal name.
@ Symbol - An “at,” or “@,” symbol is the second part of an email
address. This fits in between the username and the domain of your
email address.
Domain - The mail server is the server hosting the email account. The
top-level domain is the extension, such as .com, .net or .info.
Considerations - When you sign up for an email account, whether its free
or paid, you’re prompted first to select a username. Consider your
username carefully, especially if you plan on using your email account
to send professional emails.
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21. EMAIL
Parts of Email Address:
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Saikan1011@gmail.com
Username Symbol Domain
Mail Server

22. EMAIL
Spam Folder: The main purpose of a spam folder is to send all
your unwanted emails (internet junk mail) to a designated area.
The spam folder keeps the junk mail out of sight so it doesn’t
clutter your busy inbox.
Trash Folder: If you delete an email from your inbox, it will
initially be put into the Trash folder. The email will only be
permanently deleted if you delete it in the Trash folder or
empty the trash, or if the email's storage time has expired.
Permanently deleted email cannot be recovered.
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23. INTERNET
Advantages of the Internet:
1. Information, knowledge, and learning
2. Connectivity, communication, and sharing
3. Anonymity and making people equal
4. Address, mapping, and contact information
5. Banking, bills, and shopping
6. Selling and making money
7. Collaboration, work from home, and access to a global
workforce
8. Donations and funding
9. Internet of Things
10. Cloud computing and cloud storage 23

24. INTERNET
Disadvantages of the Internet:
1. Addiction, time-waster, and causes distractions
2. Bullying, trolls, stalkers, and crime
3. Spam and advertising
4. Pornographic and violent image
5. Never being able to disconnect from work
6. Identity theft, hacking, viruses, and cheating
7. Affects focus and patience
8. Depression, loneliness, and social isolation
9. Buying things that you don't need
10. Not a safe place for children
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25. WWW(WORLD WIDE WEB)
World Wide Web, which is also known as a Web, is a
collection of websites or web pages stored in web
servers and connected to local computers through the
internet.
URL (Uniform Resource Locator)
A Uniform Resource Locator (URL), otherwise known as a
Universal Resource Locator, is the address of a resource
on the Internet and the protocol used to access it.
It indicates the location of a web resource like a street
address indicates where a person lives physically —
because of this, an URL is often referred to as: “web
address”.
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26. DOMAIN NAME AND IPADDRESS
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A domain name is nothing but a textual version of
the IP address, this is the number which points to a
specific website.

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