What is a Computer & What Does It Do? Computer: describes a collection of hardware components that function together as a system. Refer to page COM2 Perform four basic operations: input, output, process, and storage (aka: the information processing cycle) People who use the computer directly or use the information it provides are called computer users, end users, or sometimes, just users. Green computing involves reducing the electricity consumed and environmental waste generated when using a computer.
Cont. • Computers manipulate data to create information • Data – unprocessed items (includes text, numbers, images, etc.) • Information – conveys meaning & is useful Example: Infinite Campus contains data like course codes and grades. The computer processes the data to produce your Progress Report (or other information)
How Does a Computer Know? • To perform operations, it MUST have instructions!! • Computer Program/Software: the instructions • Personal Computers and Mobile Devices • Desktop computers • Notebook computers (the lightest notebook computers, which weigh less than 3 pounds, are equipped with a 12.1-inch display) • Laptop computer • Netbook • Tablet PC • Mobile Devices • Smart phone (you might consider purchasing a second battery or an extended battery if you plan to talk on the phone more than the advertised talk time) • Portable media player • Digital camera • Plan to buy a computer that will last you for two to three years.
Computer Components • 6 Primary Components: • Input Devices • Processor (control unit and arithmetic/logic unit) • Output Devices • Storage Devices • Communication Devices • Memory – is housed in the system unit (computer case) with the processor and storage devices • Peripheral—device that connects to the system unit and is controlled by the processor in the computer. (can include input and output devices as well as some storage devices and communications devices)
Computer Components – Processor and Memory • Both are located in the “System Unit”. • Processor/CPU: interprets and carries out the instructions. Most devices connected to the computer communicate with it to carry out a task. • Memory/Random Access Memory: temporarily stores instructions, data, and the results. It fits in a slot on the motherboard (motherboard is the main circuit board of the system unit). See COM8. • Kilobyte (K or KB): about 1,000 memory locations • Megabyte (MB): about 1 million memory locations • Gigabyte (GB): about 1 billion memory locations • Terabyte (TB): about 1 trillion bytes
Computer Components - Input • Input: hardware used to enter data, programs, commands, and user responses into a computer. • Ex. Keyboard, Mouse (you can control movement of the pointer on the screen and make selections from the screen), Digital Camera, Scanner (most popular scanner is the flatbed scanner), Microphone • How is a Keyboard & Mouse different on a Personal Computer vs. Laptop? Know touchpad • Handheld computers like PDAs, smart phones, etc. can use a stylus to enter information. • Stylus looks like a small ballpoint pen that uses pressure and not ink.
Computer Components - Output • Output: makes the information available for use. (COM 9) • Printers • ink-jet and laser printers • Photo-printers • Multifunction peripheral (all-in-one device) • Display Devices: allows you to see the information • Monitor (LCD (liquid crystal display) – Most popular flat panel monitor, CRT (cathode ray tube) – looks like an older TV)
Computer Components – Storage Devices • Storage Device: stores instructions, data, and information when they are not being used in the memory. • Hard disk • Portable hard disks • External hard disk • Removable hard disk • Flash memory storage • Solid state media • Solid state drive • Memory card • USB flash drive • ExpressCard module • Optical discs • Backup is a duplicate of a file, program, or disk placed on a separate storage medium that you can use in case the original is lost, damaged, or destroyed.
Magnetic Disks – 2 types (floppy disk—floppy disk drive is a device that can read from and write on a floppy disk & hard disks), some are portable mediums. • Use magnetic particles to store items such as data, instructions, and information on a disk’s surface on tracks. • Track – narrow recording band that forms a circle on the disk.
Optical Disks: portable and is read by a laser. Ex. CD-ROM, CD-R, CD-RW, DVD-ROM, etc. • CD-ROM: read-only memory. You can use it, but you may not record on it. Ex. Software Programs • CD-R: compact disc recordable. You can record/write on it only once, then you can read from it as many times as you wish. • CD-RW: compact disc rewriteable. It is erasable and you can write on it multiple times. • DVD-ROM: stores more than any CD • DVD-R • DVD+R • DVD+RAM • Blu-ray Disc • BD-R • BD-RE • Cloud Storage—Internet service that provides hard disk storage to computer users (fee arrangements vary).
Miniature Mobile Storage Media – Allows users to transport images, documents, etc. easily. • Flash memory card, USB flash drive, etc. • Tape – magnetically coated ribbon of plastic housed in a cartridge. Stores large amt. of data at a low price. Used for long-term storage and backup.
Computer Components – Communications Devices • Communications Device: hardware component that allows a computer to send and receive data, instructions, etc. to other computers. (Ex. Modem or telephone or wireless) (If your computer has a modem, then you can access the Internet using a standard telephone line.) • Communications occur over transmission media (telephone lines, cables, satellites)
Computer Software • 2 Types of Computer Software • System Software: programs that control the operations of computer equipment. Ex. Operating System (is necessary for computer to work). • Types are Windows XP, Windows Vista, Windows 7 • Application Software: assists users with tasks. • Word Processing Software – Microsoft Word. Users can easily make changes in documents, correct spelling, change margins, add, delete, and relocate paragraphs • Spreadsheet Software – Microsoft Excel. Allows user to add, subtract, and perform user-defined calculations on rows and columns of numbers. • Database – Microsoft Access. Allows user to enter, retrieve, and update data in an organized and efficient manner. • Presentation Graphics – Microsoft PowerPoint. Allows user to create slides for use in a presentation to a group. • E-mail (electronic mail)—transmission of messages and files via a computer network.
Networks & The Internet • Network: collection of computers/devices connected together, often wirelessly, via communications devices and transmission media. • Allows users to share resources (hardware, software, data, and information). Saves time & money. • LAN – Local Area Network: connects computers in a limited geographic area. Ex. School computer lab, group of office buildings • WLAN—Wireless LAN • WAN – Wide Area Network: covers large geographical area. Ex. National organization
Internet: World’s largest network • Access provider • Can connect through an ISP (Internet Service Provider) that charges monthly fee. • Can connect through an OSP (Online Service Provider) that provides specialized content and services like news, weather, etc. AOL and MSN. • WISP – Wireless Internet Service Provider: provides wireless Internet access to computers and mobile devices like smart phones and PDA’s. AT&T, Sprint Broadband Direct, T-Mobile, and Verizon Wireless are examples.
World Wide Web: a segment of the Internet containing Web pages. (also called the Web) • A Web page can contain text, graphics, audio, and video, and has built-in connections, or links, to other Web documents. • URL: Uniform Resource Locator – web address (see next slide) • Web browser: software that allows you to read web pages (Internet Explorer) • Web site: collection of related web pages. • http:// (hypertext transfer protocol) is the communications standard used to transfer pages on the Web. (see next slide) • Searching the Web • Search engine • Search text • Subject directory
A URL consists of the following: • http://www.us-parks.com/grand_canyon/scenic_vistas.html Protocol, Domain Name, Path, Web Page Name • Web server—computer that delivers requested Web pages to your computer. • Web 2.0 refers to Web sites that provide a means for users to share personal information, allow users to modify the Web site contents, and/or have software built into the site for users to access. • Social networking Web site or online social network • Blog • E-commerce
Computer Viruses and Other Malware • Malware (Malicious software) • Worm • Trojan horse • Rootkit • Antivirus program protects a computer against viruses by identifying and removing any viruses found in memory, on storage media, or on incoming files.
Vocabulary Words database software (COM 20) desktop computer (COM 4) digital camera (COM 5) display device (COM 10) DVD+RAM (COM 17) DVD+RW (COM 17) DVD-ROM (COM 16) DVD-ROM drive (COM 16) DVD-RW (COM 17) e-commerce (COM 25) e-mail program (COM 21) end users (COM 3) ExpressCardmodule (COM 15) external hard disk (COM 12) gigabyte (GB) (COM 8) graphical user interface (GUI) (COM 18) green computing (COM 3) hard disk (COM 11) head crash (COM 11) http:// (COM 24) Hypertext Transfer Protocol (COM 24) • access provider (COM 22) • all-in-one device (COM 9) • antivirus program (COM 26) • application software (COM 18) • arithmetic/logic unit (COM 8) • backup (COM 11) • BD-RE (COM 17) • blog (COM 24) • Blu-ray Disc (COM 17) • byte (COM 8) • cloud storage (COM 17) • CD-R (COM 16) • CD-ROM (COM 16) • CD-RW (COM 16) • central processing unit (CPU) (COM 8) • cloud storage (COM 17) • communications device (COM 17) • computer (COM 2) • computer users (COM 3) • control unit (COM 8) • data (COM 3) • database (COM 20)
Vocabulary Words Continued • information (COM 3) • information processing cycle (COM 3) • input device (COM 5) • installing (COM 18) • Internet (COM 22) • ISP (Internet service provider) (COM 22) • keyboard (COM 5) • kilobyte (K or KB) (COM 8) • laptop computer (COM 4) • LCD monitor (COM 10) • local area network (LAN) (COM 21) • malware (COM 26) • megabyte (MB) (COM 8) • memory (COM 8) • memory card (COM 13) • mobile computer (COM 4) • mobile device (COM 4) • monitor (COM 10) • motherboard (COM 8) • mouse (COM 6) • multifunction peripheral (COM 9) • network (COM 21) • netbook (COM 4) • notebook computer (COM 4) • online (COM 21) • online service provider (OSP) (COM 24) • online social network (COM 24) • operating system (COM 18) • optical disc (COM 15) • output devices (COM 9) • peripheral (COM 3) • personal computer (COM 4) • photo printers (COM 9) • pixels (COM 10) • pointer (COM 6) • portable media player (COM 5) • presentation software (COM 19) • printer (COM 9) • processor (COM 8) • program (COM 18) • RAM (COM 8) • resolution (COM 10) • removable hard disk (COM 12) • rootkit (COM 26)
Vocabulary Words Continued • search engine (COM 25) • search text (COM 25) • sectors (COM 11) • smart phone (COM 5) • social networking Web site (COM 24) • software (COM 18) • solid state drive (SSD) (COM 12) • solid state media (COM 12) • spreadsheet software (COM 20) • storage device (COM 10) • storage medium (COM 10) • stylus (COM 6) • subject directory (COM 25) • system software (COM 18) • system unit (COM 8) • Tablet PC (COM 4) • terabyte (TB) (COM 8) • touchpad (COM 7) • track (COM 11) • transmission media (COM 17) • Trojan horse (COM 26) • URL (Uniform Resource Locator) (COM 24) • uninstalling (COM 18) • USB flash drive (COM 15) • users (COM 3) • utility program (COM 18) • virus (COM 26) • Web (COM 24) • Web 2.0 (COM 24) • Web address (COM 24) • Web application (COM 18) • Web browser (COM 24) • Web page (COM 24) • Web server (COM 24) • Web site (COM 24) • wide area network (WAN) (COM 22) • wireless (COM 17) • wireless Internet service provider (COM 24) • wireless LAN (WLAN) (COM 21) • word processing software (COM 19) • worksheet (COM 20) • World Wide Web (COM 24) • worm (COM 26)