Computer Literacy

 

Viruses:

  1. Virus-a potentially damaging computer program that copies itself from computer to computer.
  2. Worm-a small piece of software that uses network and security holes to replicate itself-causing damage.
  3. Trojan Horse- a program that claims to do one thing and does damage instead
  4. Email Virus- moves around in email messages. Usually replicated by automatically mailing itself using the victim�s address book.
  5. Spyware-is a type of malicious software designed to intercept or take partial control of a computer�s operation without the informed consent of the user.
  6. Firewall-a hardware or software barrier between your PC and the Internet. The goal of the firewall is to prevent unauthorized access by hackers, viruses and other Internet threats. (Filter-sips through computer to prevent any garbage from coming in or out)
  7. Spam-junk email or unsolicited e-mail on the Internet.
  8. Phishing- is e-mail fraud where legitimate-looking e-mails are received that appears to come from well-known and trustworthy Web sites. The sender is attempting to illegally gather personal and financial information from you. If you receive an email asking for personal information, do not send that information unless you are sure it is a trustworthy site. 

  9. File Sharing Risks

            A file is a named collection of data

A data file contains electronically encoded information, such as texts, graphics or numbers, but does not contain the instructions, which tell the computer what to do.

An executable file contains the instructions, which tell the computer how to perform a specific task.

File extensions help describe the content of a file, and most modern computers use them to decide with which program to run the file.

�      . exe-executable file which starts a program .Jpg-graphic

�      . mid-sound file (midi) or .mp3, .bmp-graphic

�      . doc-Word or document .ppt = PowerPoint, .xls = Excel

�      . sys- system file .bat = bat file  .txt = text .htm or .html is hyper text markup language which is a web page

  1. Backup- the process of storing data in more than one place to protect it from damage or loss. Backup your computer regularly.   

  2. Security or program updates- these are updates issued by the software creators. They keep you up to date about any important changes to their program that may impact the programs functioning. Not installing the security updates may make your computer vulnerable to attacks by hackers.

 

  1. Memory is measured in bytes

There are 8 Bits in a byte and 4 bits is a nibble or a half byte.

Each bit is a zero or one or an on or off signal. The zero is the off signal the one is the on signal.    

Kilobyte- 1024 bytes where 1024 is usually rounded to 1000

Megabyte- around one million bytes or 1024 x 1024 or 1000 kilobytes

Gigabyte- around 1 billion bytes or 1024 x 1024 x 1024 or 1,000 megabytes

Terabyte- around 1 trillion bytes or 1024 x 1024 x 1024 x 1024      

RAM is temporary memory. It disappears when you turn off the computer-random access memory

ROM is permanent memory- read only memory-It cannot be changed. CD-ROMs cannot be changed once data is saved on them. The BIOS or startup routine of the computer is made of instructions that are saved in ROM. They are permanent and are executed each time you start up the computer.

  1. Microprocessor = Chip- is a piece of silicon (from sand) that contains many integrated circuits.

  2.  CPU- Central Processing Unit- often referred to as the brain s of the computer

  3. CRT- a desktop monitor- Cathode Ray Tube
  4. Boot Up- load a computer�s operating system
  5. Hardware- physical devices which make up the computers and its peripherals (anything that works/attached to the CPU). Input devices versus output devices. Can you give examples?  Monitor
  6. Operating System- OS-main program of the computer that schedules tasks, manages storage and handles communication with peripherals. All applications must communicate with the operating system. Windows and UNIX, and Linnex are examples.
  7. Hard Drive- a disk drive that reads and writes to a hard disk.  (Floppy drive- disk drive where we use a floppy disk)

 

 

COMPUTER:     

A computer has an input device (key board, mouse, USB, disk, CD) and a CPU that processes information, stores it in memory then gives you in output via an output device (speakers).  Computers don�t understand words they only understand 0 (off) and 1 (off). (Binary Digits)

 

Sites:

WWW.FOLDOC.ORG

WWW.WHATIS.COM

WWW.WEBOPEDIA.COM

 

Return to Freshman Review Sheets

� Review Sheets Central

www.reviewsheetscentral.com