Introduction to

Computers

What are they?

Electronic devices operating under the control of instructions stored in its own memory that can:• accept data (input)• process the date according to

specified rules (process)• produce results (output)• store the results for future use

(storage)

Different Computer Types

Personal Computers• Apple• Dell• ToshibaPhonesCameras

ComponentsSystem Unit (Computer Case)MotherboardProcessor aka CPUMemory/Storage RAM ROM Hard Drive/Disk External Devices

System Unit/Computer Case

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Lot’s of hardware components are found inside the computer case

What’s under the hood?

Motherboard

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Processor

7Intel DP35DPM Motherboard

Intel Core 2 DuoE6850 Processor

Interprets and carries out the basic instructions that operate a computer.

Measuring Memory

1 gigabyte can hold about 500,000 letters-sized pages of

text/information

• Byte = one character such as the letter A

• Kilobyte (KB) = 1,024 bytes• Megabyte (MB) = 1 million

bytes• Gigabyte (GB) = 1 billion

bytes• Terabyte (TB) = 1 trillion

bytes

Memory is measured in bytes.

RAM (Memory)RAM doesn’t rememberDDR2 is the current “best” typeMore is betteroWindows XP can run with 512MB but

1GB is betteroWindows Vista and Windows 7 can run

with 1 GB but 2GB is better

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Hard Drive/ Hard Disk

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500 GB drive on a desktop computer is a good starting point

Has movable parts that either reads data from or writes data to a disk.

When an application is downloaded to the computer it is written on the hard drive so it can be accessed whenever needed.

Data on Hard disk transfers to RAM for easier access by a processor.

Input Devices

Hardware components that allow data and instruction to be enteredKeyboardMouseMicrophone

Output Devices

Hardware components that convey information to one or more people Printer Monitor Speakers

Storage Devices

Hardware components that stores information after a computer is powered off. External Hard Drive USB Drive Cloud Storage

Cloud StorageCloud storage is a model of networked

enterprise storage

Data is stored in virtualized pools of storage which are generally hosted by third parties

Hosting companies operate large data centers, and people buy or lease storage capacity from them.

Computer Software

System software consists of programs to control the operations of computer equipment.

◦Such as an Operating System

Application software consists of programs that tell a computer how to produce information.

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Operating SystemSet of programs that

coordinates all the activitiesamong computer hardware devices.

Provides a means for users to communicate with the computer and other software.

Instructions in the operating system tell the computer how to perform the functions of loading, storing, and executing an application program and how to transfer data.

Operating System FactsWhen a computer is turned on, the

operating system is loaded into the computer’s memory from auxiliary storage, a process called booting.

Most computers use an operating system that has a graphical user interface (GUI).

GUI allows users to interact with electronic devices with images rather than text commands.

A GUI represents the information and actions available to a user through graphical icons and visual indicators.

Application Software

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NetworkCollection of computers and devices connected via communications media and devices

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Types of Networks

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Local Area Network (LAN) Wide Area Network (WAN)

A local area network (LAN) connects computers in a limited geographic area

A wide area network (WAN) covers a large geographical area

The World Wide WebThe Internet is the world’s largest network

A Web page is a document that contains text, graphics, sound, and/or video and has built-in connections, or hyperlinks to other Web documents

A Web site is a related collection of Web pages

You access and view Web pages using a software program called a Web browser

A Web page has a unique address, called a Uniform Resource Locator (URL) 21

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Search EnginesSearch engines are programs that find websites, web pages, images, videos, news, maps and other information related to a specific topic.

Searches help you find pictures, research, and identify related information based on words

Social MediaForms of electronic communication through which users create online communities to share information, ideas, personal messages, and other content.

Types of Social Media

MalwarePrograms or files that are developed for

the purpose of doing harm.

Acts without a user’s knowledge and deliberately alters a computer’s operations.

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Types of Malware

◦Viruses Code connected to a file or program Cannot spread without human interaction

◦Worms Similar to a virus Does not require human interaction to spread

Copies itself repeatedly Can shut down a network

Types of Malware

◦Trojan Horse Disguised as helpful software but is not!

Will not replicate or spread

◦Rootkit Hides in computer Someone can access remotely and take

over full control of computer.

How to tell if you’ve been invaded?Strange new things pop up on your

system◦New toolbars, new homepage, new

folders or files

System is slow◦Hard drive light is busy a lot when you

are not running any programs

System is unstable◦Applications don’t run◦Windows crashes a lot 30

1. Never start a computer with removable media inserted in the drives

2. Never open an e-mail attachment unless it is from a trusted source.

3. Install an antivirus program on all of your computers.

4. Delete or quarantine any infected e-mails, downloads or threats to your computer

Tip

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5. Scan all downloaded programs for viruses and other malware.

6. Before using any removable media, scan the media for malware.

7. Install a personal firewall program.

8. Stay informed about new virus alerts and virus hoaxes.

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Computer Maintenance Don’t throw away starter software

Shut down your computer – at least once a week

Uninstall programs you are not using

Backup your computer files monthly

Keep all working files in one folder instead of your desktop such as My Documents. Easier to find & back up files Don’t put personal files on the C

Drive

Computer Maintenance

Physically clean your computer/accessories – wipe down the screen, use forced air to remove dust from keyboard

Clean out your temporary files on your computer and internet

Defragment your computer

Change your passwords regularlyDo not use personal information as a

passwordUse different passwords