Introduction to Computers
Where can you find computers?
Computers are everywhere.
What is computer literacy?
If you are computer literate, you have knowledge and understanding of computers and their uses.
What is a computer?
An electronic machine, operating under the control of instructions stored in its own memory
- Accepts data
- Manipulates the data according to specified rules
- Produces results
- Stores the results for future use
What are data and information?
Data-collection of raw facts, figures and symbols.
Information-data that is organized, meaningful and useful.
Who is a user?
- Someone that communicates with a computer
- Someone who uses the information it generates
What are hardware and software?
Hardware- The electric, electronic, and mechanical equipment that makes up a computer.
Software- The series of instructions that tells the hardware how to perform tasks.
What are common computer hardware components?
Printer, speaker, pc camera, system unit, modem, mouse, digital camera, scanner, keyboard, microphone.
What is an input device?
Any hardware component that allows a user to enter data and instructions into a computer.
What is an output device?
Any hardware component that can convey information to a user.
What is the system unit?
- Sometimes called a chassis
- A box-like case made from metal or plastic that protects the internal electronic components of the computer from damage
- Circuitry in the system unit usually is part of or is connected to a circuit board called the motherboard
What are two main components on the motherboard?
Central Processing Unit (CPU)
- Also called a processor
- Electronic device that interprets and carries out the basic instructions that operate the computer
Memory
- Temporary holding place for data and instructions
What is storage?
Holds data, instructions, and information for future use.
Storage Medium
- Physical material on which a computer keeps the data, instructions and information
Storage Device
- Records and retrieves items to and from a storage medium
- Devices often function as source of input because they transfer items from storage into memory
What is a network?
Two or more computers connected together via communications media and devices. The most widely known network is the Internet.
What is a computer program?
A series of instructions that tells the hardware of a computer what to do.
What is system software?
Programs that control the operations of the computer and its devices.
Operating System (OS)
Set of programs containing instructions that coordinate all the activities among computer hardware devices.
What is a graphical user interface (GUI)?
Allows you to interact with the software using visual images such as icons.
What is a command line interface (CLI)?
An interface to the Operating System where the user typically enters commands using the keyboard at the command line prompt.
What is application software?
Programs that perform specific tasks for users. E.g. word processing software, spreadsheet software, database software, and presentation graphics software.
What is networking?
Two or more devices that communicate each other and share resources.
What is the Internet?
The internet is a global network of networks. (or)
The world wide interconnected system of computer networks.
Why do users access the Internet?
- Information
- Shopping
- Meeting people
- Entertainment
What is the World Wide Web (WWW)?
Billions of documents, called Web pages, that are linked together on computers throughout the world
Web site
- Collection of related web pages
Web page
- Contains text, graphics, sound, or video and has connections to other Web pages.
Web browser
- Program used to access and view Web pages.
What is the digital divide?
Idea that you can separate people of the world into two distinct groups
- Those who have access to technology with the ability to use it
- Those who do not have access to technology or are without the ability to use it
Operating Systems and Utility Programs
What is software?
- The series of computer-language coded instructions that tells the computer how to perform tasks
- Two types of software
- Application software
- System software
What is system software?
- Programs that control the operations of the computer and its devices
- Interface between user, application software, and hardware
- Two types are operating systems and utility programs
What is an operating system (OS)?
- Set of programs containing instructions that coordinate all the activities among computer hardware resources
- Required for a computer to work
What are the functions of an operating system?
· Memory management
· Startup computer
· Program management
· Schedule jobs
· Configure devices
· Access the web
· Administer security
· Control network
· Monitor performance (monitoring)
· Provide user interface
Where is the operating system located?
- Resides on computer’s hard disk in most cases
- May reside on a ROM chip on handheld computers
What is booting?
The process of starting or restarting a computer
Cold boot- Process of turning on a computer after it has been powered off completely.
Warm boot- Process of restarting a computer that is already powered on. Also called a warm start.
What is the kernel?
The core of an operating system
- Manages memory and devices
- Maintains the computers clocks
- Starts applications
- Assigns the computers resources, such as devices, programs, data, and information
Each time you boot a computer, the kernel and other frequently used operating system instructions are loaded
- Loading a file means the file is copied from the hard disk to the computer's memory
Memory resident
- Remains in memory while the computer is running
- The kernel is memory resident
Non-resident
- Instructions remain on the hard disk until they are needed
- Other parts of the operating system are nonresident
How does a personal computer boot up?
- The power step
- The supply sends a processor
BIOS basic input/output system- Firmware that contains the computer's startup instructions.
- The BIOS performs the POST, which checks components such as the mouse, keyboard connectors, and expansion cards
- The results of the POST are compared with data in the CMOS chip
CMOS chip- Stores configuration information about the computer. Also detects new devices connected to the computer.
- The BIOS looks for the system files in drive A (floppy disk drive) and then drive C (hard disk)
System files- Specific operating system files loaded during start up.
- The boot program loads the kernel of the operating system into RAM from storage (hard disk). The operating system in memory takes control of the computer
- The operating system loads configuration information and displays the desktop on the screen. The operating system executes programs in the StartUp folder
Registry- Several files that contain the system configuration information. Registry is constantly accessed during the computer's operation.
StartUp folder- Contains a list of programs that open automatically when you boot the computer.
What is a user interface?
Controls how you enter data and instructions and how information displays on the screen.
What is multitasking?
Allows a single user to work on two or more applications that reside in memory at the same time.
What are other program management features of operating systems?
Multiuser - Operating system enables two or more users to run a program simultaneously.
Multiprocessing- Operating system can support two or more processors running programs at the same time.
Fault-tolerant computer
- Continues to operate even if one or its components fails
- Computer has duplicate components such as processors, memory, and disk drives
What is virtual memory (VM) management?
The operating system allocates a portion of a storage medium, usually the hard disk, to function as additional RAM. When system declares storage memory as a (RAM) it is called (VM).
What is a device driver?
- Program that tells the operating system how to communicate with a device
- Also called a driver
- Each device requires its own driver
What is Plug and Play?
- The computer recognizes a new device, loads the necessary drivers automatically, and checks for conflicts with other devices
- Supported by most devices and operating systems today
What is a network operating system?
- An operating system that supports a network
- Also called a network OS or NOS
- A network is a collection of computers and devices connected together via communications media and devices
What is DOS (Disk Operating System)?
- Refers to several single user operating systems developed in the early 1980s for personal computers
- Two more widely used versions were PC-DOS and MS-DOS, both developed by Microsoft
- Used a command line interface and added a menu-driven interface in later versions
What is Windows?
Developed by Windows to meet the need for an operating system that had a GUI
Windows 3.x
- Refers to three early versions of Microsoft Window that were operating environments with DOS
- A GUI that works in combination with an operating system to simplify its use
Windows 95
- A true multitasking operating system with downward compatibility for DOS and Windows 3.x
Windows NT Workstation
- A client operating system that could connect to a Windows NT server Used a Windows 95 interface
What is Windows Millennium Edition (ME)?
- An operating system that has features specifically for the home users
- Also called Windows Me
- Includes multimedia features
What is UNIX?
- A multitasking operating system developed in the early 1970s by scientists at Bell Laboratories
- Command-line interface
What is an embedded operating system?
- The operating system on most handheld computers and small devices
- Resides on a ROM chip
- Palm OS & Pocket PC OS
What is a utility program?
A program that helps you to perform maintenance or correct problems with your computer system
Examples
- Disk defragmenters, system profilers, virus scanners, binary/hex/text editor, archive, file compression, File viewer, Diagnostic utility, Uninstaller, Backup Utility, Screen Saver
