1. Essential Computer Concepts
Study Guide

2. Types of Computers Types of computers include (but are not limited to)
Personal computers
Desktop
Laptop (notebooks)
Tablet PC
Hand-held
PDA’s (personal digital assistants)
MP3 players
Cell phones
Mainframe computers- used by businesses and government to process large amounts of information
Supercomputers – largest, fastest and most powerful in existence

3. Computer System Components
Computer systems include hardware and software.
Hardware refers to the physical components
Software refers to the programs or list of instructions that the computer needs to perform a specific task.
System software is computer software designed to operate and control the computer hardware and to provide a platform for running application software, such as the operating system
Application software is software you use to create documents, spreadsheets, presentations, etc.
The Operating System allocates system resources, manages storage space, maintains security, detects equipment failure, and controsl basic input and output.
Data refers to information (words, numbers, graphics, etc.)
Processing is modifying data

4. Computer Systems Components (continued)
Motherboard is where processing tasks occur
Main electronic component
Is a circuit board
Microprocessor (CPU)
Transistors and electronic circuits on a silicon chip
Mounted on the motherboard
Responsible for executing instructions to process information

5. Computer System Components (continued)
Cards are removable circuit boards to expand the capabilities of the motherboard
Input is the data or instructions you put into the computer using keyboard, mouse, touchpad, scanner, camera, microphone
Output is the results of the computer processing. Devices used include printers, monitors, speakers.
Peripheral devices such as mouse, keyboards printers and storage devices accomplish input, output and storage functions
Commands are input instructions

6. Understanding Memory Types of memory include the following:
Random access memory (RAM) –
temporarily holds programs and data while the computer is on and allows the computer to access that information randomly.
Consists of chips on cards that plug into the motherboard.
When the computer is off RAM is empty
Cache memory (RAM cache or CPU cache) –
Special high speed memory chip on the motherboard that stores frequently accessed and recently accessed data and commands

7. Understanding Memory
Virtual memory – space on the computer’s storage devices that simulate additional RAM.
It is much slower than RAM
Read only memory (ROM) – is a chip on the motherboard that has been prerecorded with data that gives instructions (BIOS or basic input/output system) used to check the computer system’s components to make sure they are working and to activate the essential software that controls the processing function when the computer is turned on or booted up.
ROM never changes and it remains intact when the computer is turned off. It is called non-volatile or permanent memory

8. Understanding Storage Media
The types of storage media are:
Magnetic storage devices
Hard disk – magnetic oxide-covered metal platters sealed inside the computer
Tape – used to make back-up copies of data stored on hard drives
Optical storage devices – polycarbonate discs coated with a reflective metal on which data is recorded using laser technology
CD (Compact disc) – can store 700 MB of data
DVD- can store between 4.7 and 15.9 GB of data
Blu-ray discs and HD-DVD – can store between 15 and 50 GB of data

9. Understanding Storage Media
Flash Memory
Flash memory cards – used in digital cameras, handheld computers and other devices
USB flash storage device – can store 32 MB – 16 GB of data. Popular for use as a secondary or backup storage device for date stored on a hard disk drive

10. Security Threats
Security refers to the steps a computer owner takes to prevent unauthorized use of or damage to the computer.
Malware is a broad term that describes any program that is intended to cause harm or convey information to others without the owner’s permission.
Virus is a program which instructs your computer to perform destructive activities.
Spyware tracks a computer user’s Internet usage and send this data back to the company or person that create it. It is contained in other software.

11. Security Threats (continued)
Adware is software installed to generate advertising revenue for the program's creator
Spoofed site - a website set up to look exactly like another website to convince customers to enter personal information
Phishing - The practice of sending s to customers or potential customers of a legitimate Web site asking them to click a link in the
Antivirus software protects against viruses, worms and Trojan horse types of malware