Introduction To The World Of Technology Chapter 1 PDF

INTRODUCTION TO THE WORLD OF TECHNOLOGY CHAPTER 1 Reference Book: Morley, D. and C.S. Parker. Understanding Computers: Today and Tomorrow, Comprehensive.  WHAT IS A COMPUTER AND WHAT DOES IT DO? ▪ A computer is a programmable, electronic device that accepts data, performs operatio...

INTRODUCTION TO THE WORLD OF TECHNOLOGY CHAPTER 1 Reference Book: Morley, D. and C.S. Parker. Understanding Computers: Today and Tomorrow, Comprehensive.  WHAT IS A COMPUTER AND WHAT DOES IT DO? ▪ A computer is a programmable, electronic device that accepts data, performs operations on that data, presents the results, and stores the data or results as needed. ▪ The four operations described in this definition are considered the four primary operations of a computer. ▪ They can be defined as follows: ➤Input—entering data into the computer. ➤Processing—performing operations on the data. ➤Output—presenting the results. ➤Storage—saving data, programs, or output for future use. ▪ Because a computer is programmable, it will do whatever the instructions—called the program—tell it to do. ▪ The programs used with a computer determine the tasks the computer is able to perform. Example: For an example, look at a supermarket barcode reader to see how it fits this definition of a computer. First, the grocery item being purchased is passed over the barcode reader—input. Next, the description and price of the item are looked up— processing. Then, the item description and price are displayed on the cash register and printed on the receipt—output. Finally, the inventory, ordering, and sales records are updated—storage. ▪ This progression of input, processing, output, and storage is sometimes referred to as the IPOS cycle or the information processing cycle. ▪ In addition to these four primary computer operations, today’s computers almost always perform communications functions, such as sending or retrieving data via the Internet, accessing information located in a shared company database, or exchanging data or e-mail messages with others. ▪ Therefore, communications—technically an input or output operation, depending on which direction the information is going—is often considered the fifth primary computer operation.  DATA VS. INFORMATION ▪ As just discussed, a user inputs data into a computer, and then the computer processes it. ▪ Almost any kind of fact or set of facts can become computer data, such as the words in a letter to a friend, the numbers in a monthly budget, the images in a photograph, the notes in a song, or the facts stored in an employee record. ▪ When data is processed into a meaningful form, it becomes information. ▪ Information is frequently generated to answer some type of question, ▪ such as How many of a restaurant’s employees work less than 20 hours per week? How many seats are available on a particular flight from Los Angeles to San Francisco? ▪ Of course, you don’t need a computer to process data into information; for example, anyone can go through time cards or employee files and make a list of people who work a certain number of hours. If this work is done by hand, however, it could take a lot of time, especially for a company with a large number of employees. ▪ Computers, however, can perform such tasks almost instantly, with accurate results. ▪ Information processing (the conversion of data into information) is a vital activity today for all computer users, as well as for businesses and other organizations. Computer Generations (Prepare it for discussion)  HARDWARE ▪ The physical parts of a computer (the parts you can touch and discussed next) are called hardware. ▪ There are hardware devices associated with each of the five computer operations previously discussed (input, processing, output, storage, and communications). Input Devices ▪ An input device is any piece of equipment that is used to input data into the computer. The input devices shown in Figure are a keyboard and mouse and an integrated video camera. ▪ Other common input devices include microphones, scanners, digital pens and styluses, touch pads and touch screens, fingerprint readers, and gaming controllers. Processing Devices ▪ The main processing device for a computer is the central processing unit (CPU). The CPU is located inside the system unit and performs the calculations and comparisons needed for processing; it also controls the computer’s operations. ▪ For these reasons, the CPU is often considered the “brain” of the computer. Also involved in processing are various types of memory that are located inside the system unit and used to store data and instructions while the CPU is working with them, as well as additional processors such as the graphics processing unit (GPU). Output Devices ▪ An output device accepts processed data from the computer and presents the results to the user, most of the time on the display screen (monitor), on paper (via a printer), or through a speaker. ▪ Other common output devices include headphones and headsets (used to deliver audio output to a single user) and data projectors (used to project computer images onto a projection screen). Storage Devices ▪ Storage devices (such as DVD drives and flash memory card readers) are used to store data on or access data from storage media (such as DVD discs and flash memory cards). ▪ Some storage hardware (such as a hard drive or a USB flash drive) includes both a storage device and storage medium in a single piece of hardware. ▪ Storage devices are used to save data, program settings, or output for future use; they can be installed inside the computer, attached to the computer as an external device, or accessed remotely through a network or wireless connection. Communications Devices ▪ Communications devices allow users to communicate electronically with others and to access remote information via the Internet or a home, school, or company computer network. ▪ Communications hardware includes modems (used to connect a computer to the Internet), network adapters (used to connect a computer to a computer network), and routers (used to create a small network so a variety of devices can share an Internet connection and data). ▪ A variety of modems and network adapters are available because there are different types of Internet and network connections—a modem used to connect to the Internet via a wireless connection and that also contains a built-in wireless router is shown in Figure. SOFTWARE ▪ The term software refers to the programs or instructions used to tell the computer hardware what to do. Software is traditionally purchased on a CD or DVD or is downloaded from the Internet; in either case, the software typically needs to be installed on a computer before it can be used. ▪ Software can also be run directly from the Internet (via Web pages) without being installed on your computer; this is referred to as cloud software, Web-based software, Software as a Service (SaaS), and cloud computing. ▪ Computers use two basic types of software: system software and application software. The differences between these types of software are discussed next. System Software ▪ The programs that allow a computer to operate are collectively referred to as system software. ▪ The main system software is the operating system, which starts up the computer and controls its operation. ▪ Common operating system tasks include setting up new hardware, allowing users to run other software, and allowing users to manage the documents stored on their computers. Without an operating system, a computer cannot function. ▪ Common desktop operating systems designed for personal computers are Windows, OS X, and Linux; these and other operating systems (such as Android, iOS, and other mobile operating systems used with smartphones and other mobile devices. ▪ When a computer or other computing device is powered up, it begins to boot. ▪ During the boot process, part of the computer’s operating system is loaded into memory, the computer does a quick diagnostic of itself, and then it launches any programs—such as security software—designated to run each time the computer starts up. ▪ A username and password may be required to log on to the computer in order to finish the boot process. ▪ Once a computer has booted, it is ready to be used and waits for input from the user. ▪ Most software today uses a variety of graphical objects (such as icons, buttons, and tiles) that are selected with the mouse (or with a finger or stylus for a computer that supports touch or pen input) to tell the computer what to do. ▪ For instance, the Windows desktop (the basic workspace for computers running the Windows operating system; that is, the place where documents, folders, programs, and other objects are displayed when they are being used), along with some common graphical objects used in Windows and many other software programs, is shown in Figure. Application Software (Apps) ▪ Programs ( designed to allow people to perform specific tasks using a computer, such as creating letters, preparing budgets, managing inventory and customer databases, playing games, watching videos, listening to music, scheduling appointments, editing digital photographs, designing homes, viewing Web pages, burning DVDs, and exchanging e-mail are called application software (apps). ▪ Apps are launched via the operating system, such as by using the Windows Start menu on Windows computers. ▪ There are also application programs that help users write their own programs in a form the computer can understand using a programming language like Visual Basic, COBOL, C++, Java, or Python. ▪ Some languages are traditional programming languages for developing applications; others, such as markup and scripting languages like HTML, XHTML, and JavaScript, are designed to be used to create Web pages. Programming, markup, and scripting languages ▪ COMPUTER USERS AND PROFESSIONALS Computer users are the people who use computers to perform tasks or obtain information. Anyone who uses a computer is a computer user, including an accountant electronically preparing a client’s taxes, an office worker using a word processing program to create a letter, a supervisor using a computer to check and see whether or not manufacturing workers have met the day’s quotas, a parent e-mailing his or her child’s teacher, a college student researching a topic online, a doctor updating a patient’s electronic medical record, a child playing a computer game, and a person shopping online. ▪ Programmers, on the other hand, are computer professionals who write the programs that computers use. Other computer professionals include systems analysts (who design computer systems to be used within their companies) computer operations personnel (who are responsible for the day-to-day computer operations at a company, such as maintaining systems or troubleshooting user-related problems), and a security specialists (who are responsible for securing the company computers and networks against hackers and other intruders.  COMPUTERS TO FIT EVERY NEED ▪ The types of computing devices available today vary from the tiny computers embedded in consumer products, to the pocket-sized mobile devices that do a limited number of computing tasks, to the powerful and versatile desktop and portable computers found in homes and businesses, to the super powerful computers used for scientific research and to control critical government systems. ▪ Computers are generally classified by the following categories, based on size, capability, and price. ➤Embedded computers—tiny computers embedded into products to perform specific functions or tasks for that product. ➤Mobile devices—smartphones, small tablets, and other small personal devices that contain built-in computing or Internet capabilities. ➤Personal computers—fully functioning portable or desktop computers that are designed to be used by a single individual at a time. ➤Servers—computers that host data and programs available to a small group of users. ➤Mainframe computers—powerful computers used to host a large amount of data and programs available to a wide group of users. ➤Supercomputers—extremely powerful computers used for complex computations and processing. ▪ In practice, classifying a computer into one of these six categories is not always easy or straightforward. ▪ For example, some high-end personal computers today are as powerful as servers, and some personal computers today are the size of a smartphone or smaller. ▪ In addition, new trends impact these categories. For example, small tablet devices (sometimes called media tablets) are considered mobile devices because they are only slightly larger than a smartphone, are typically used primarily for viewing Web content and displaying multimedia content instead of general- purpose computing, and usually run a mobile operating system. ▪ However, larger, more powerful tablet computers running a desktop operating system are typically considered personal computers. ▪ So even though the distinction between some of the categories (particularly mobile devices and personal computers) is blurring, these six categories are commonly used today to refer to ▪ groups of computers designed for similar purposes. Embedded Computers ▪ An embedded computer is a tiny computer embedded into a product designed to perform specific tasks or functions for that product. ▪ For example, computers are often embedded into household appliances (such as dishwashers, microwaves, ovens, coffeemakers, and so forth), as well as into other everyday objects (such as thermostats, treadmills, sewing machines, DVD players, and televisions), to help those appliances and objects perform their designated tasks. ▪ Cars also use many embedded computers to assist with diagnostics, to notify the user of important conditions (such as an underinflated tire or an oil filter that needs changing), to facilitate the car’s navigational and entertainment systems, and to control the use of the airbag and other safety devices (such as cameras that alert a driver that a vehicle is in his or her blind spot or that assist with parking). ▪ Self-driving cars , which are currently being road tested, contain a large number of embedded computers (as well as lasers, sensors, cameras, and other technology) to enable the car to safely operate without a driver. Embedded computers are designed for specific tasks and specific products and so cannot be used as general-purpose computers.