Lesson 1: Introduction To Computer Systems PDF

# Lesson 1: Introduction To Computer Systems ## Lesson 1A: Exploring Computers And Their Uses - **Overview: Computers In Our World** - Computers are everywhere, including cars, home appliances, and alarm clocks. - They have reshaped people's lives at home, work, and school in the last two...

# Lesson 1: Introduction To Computer Systems ## Lesson 1A: Exploring Computers And Their Uses - **Overview: Computers In Our World** - Computers are everywhere, including cars, home appliances, and alarm clocks. - They have reshaped people's lives at home, work, and school in the last two decades. - The vast majority of businesses use computers, and most are networked both internally and externally. - Over half of all homes have at least one computer, and most are connected to the internet. - Workers who once had little use for technology now interact with computers almost every minute of the workday. - **Exploring The Many Types Of Computers** - Although this lesson focuses on personal computers (PCs), you'll learn about the wide variety of computers that people use, and why they use them. - You'll learn that all computers, regardless of their size or purpose, operate on the same fundamental principles and are made from the same basic components. - **Objectives** - Define the word "computer". - Discuss various ways that computers can be categorized. - Identify six types of computers designed for individual use. - Identify four types of computers used primarily by organizations. - Explain the importance of computers in today's society. - Describe how computers are used in various sectors of our society. - **The Computer Defined** - A computer is an electronic device that processes data, converting it into useful information. - Any computer, regardless of its type, is controlled by programmed instructions which give the device a purpose and tell it what to do. - **Digital Computers** - Digital computers are so called because they work "by the numbers". - They break information into tiny units and use numbers to represent them. - They work in very strict sequences of steps, processing each unit of information individually, according to the instructions they need to follow. - **Analog Computers** - Analog computers work in a very different way than digital computers. - Early computers were analog systems. - The way that digital and analog computers represent data differentiates them. - **Digital:** Digital systems represent data as having one distinct value or another. - **Analog:** Analog systems represent data as variable points along a continuous spectrum of values. - Early analog computers were mechanical devices using motors and gears to perform calculations. - A familiar type of analog computer is the old-fashioned slide rule. - **Categorizing Computers** - Computers can be categorized in several ways. - Some computers are designed for use by one person, some for groups of people, and some aren't used by people at all. - They can also be categorized by their power, meaning the speed at which they operate and the types of tasks they can handle. - Computers can be subcategorized by price, the types of hardware they contain, the kinds of software they can run, and so on. ## Lesson 1B: Looking Inside The Computer System - **Objectives** - List the four parts of a complete computer system. - Name the four phases of the information processing cycle. - Identify four categories of computer hardware. - List four units of measure for computer memory and storage. - Name the two most common input and output devices. - Name and differentiate the two main categories of storage devices. - Name and differentiate the two main categories of computer software. - Explain the difference between data, information, and programs. - Describe the role of the user, when working with a personal computer. - **The Parts of a Computer System** - Every computer is part of a system that consists of four parts. - **Hardware:** The mechanical devices that make up the computer. - **Software**: A set of instructions that tells the computer what to do. - **Data**: Individual facts or pieces of information that by themselves may not make much sense to a person. - **User**: The person interacting with the computer. - **The Information Processing Cycle** - The information processing cycle is a set of steps that a computer follows to receive data, process it according to instructions from a program, display the resulting information to the user, and store results. - **Input:** The computer accepts data from some source, such as the user or a program, for processing. - **Processing:** The computer's processing components perform actions on the data, based on instructions from the user or a program. - **Output:** The computer may be required to display the results of its processing as text, numbers, or graphics on the computer screen or as sounds from its speaker. - **Storage:** The computer permanently stores the results of its processing on a disk, tape, or some other kind of storage medium. - **Essential Computer Hardware** - Every computer has a processor, memory, input and output devices, and storage. Devices fall into one of these four categories. - **Processor:** The brain of the computer, it organizes and carries out instructions that come from either the user or the software. - **Memory:** A set of chips that store data and/or program instructions, either temporarily or permanently. - **Input and Output Devices:** Input Devices accept data and instructions from the user or a program that allows the computer to receive information, and Output Devices present processed data to the user or to another computer. - **Storage Devices:** Used to hold program files and related data when they are not in use. - **Memory Devices** - **Random Access Memory (RAM)**: RAM is volatile, meaning that it loses its contents when the computer is shut off or if there is a power failure. - **Read-Only Memory (ROM)**: ROM is non-volatile, meaning the data is permanently stored even when the computer is shut off. - **Input and Output Devices** - **Input Devices:** Devices used to accept data and instructions from the user or another computer system. - Keyboard, Mouse, Trackball, Touchpad, Joystick, Scanner, Digital Camera, Microphone. - **Output Devices:** Devices used to present processed data to the user or to another computer system. - Monitor, Printer, Speakers, Touch Screen. - **Storage Devices** - Storage devices retain data permanently. - **Magnetic storage**: Magnetic storage is the most common; a disk, which spins around its center stores data. - **Optical Storage**: Optical storage devices use lasers to read data from or write data to a reflective surface. - **CD-ROM drive:** Plays compact discs, which are identical to audio CDs. - **CD-Recordable (CD-R)**: A CD-R drive can write data to and read data from a compact disc. - **DVD Drive:** A DVD drive can store an entire full-length movie on a digital video disc (DVD), which can hold a minimum of 4.7 GB of data and as much as 17 GB. - **Software** - Software is a set of instructions that tells the computer what to do. - **System Software**: Software that controls the computer's hardware or that can be used to maintain the computer. - **Operating System (OS):** The operating system tells the computer how to use its own components and acts as an interpreter between the hardware, application programs, and the user. - **Network Operating System:** Software that allows computers to communicate and share data across a network. - **Utility**: A program that makes the computer system easier to use or that helps troubleshoot hardware problems. - **Application Software**: Software that tells the computer how to accomplish specific tasks. - **Word Processing Software:** Word processing software for creating text-based documents. - **Spreadsheet Software:** Spreadsheet software for creating numeric-based documents such as budgets or balance sheets. - **Database Management Software:** Database management software for building and manipulating large sets of data. - **Presentation Software:** Presentation software for creating and presenting electronic slide shows. - **Graphics Programs:** Graphics programs for designing illustrations or manipulating photographs, movies, or animation. - **Multimedia Authoring Applications:** Multimedia authoring applications for building digital movies. - **Entertainment and Education Software:** Games and Web browsers. - **Computer Data** - Data is a piece of information or a fact, that doesn't make sense on its own, but can be organized into groups that become information. - A **file** is simply a set of data that has been given a name. - **Document:** A file that the user can open and use can usually be called a document. - When data is organized into groups, such as a blueprint or a chart, it becomes useful information. - **Computer Users** - Personal computers are designed to work with a human user. - The user is a critical part of a complete computer system. - Users have several roles when working with a computer. - Setting up the system - Installing software - Running programs - Managing Files - Maintaining the system - **"Userless" Computers** - Some computers require no human interaction once they have been installed and started up. - They perform a specific set of tasks, such as monitoring a function or checking for a failure. - They are not set up for human interaction, except as needed for system configuration or maintenance. - **Computers In Your Career** - Computers are making an impact in all professions, not just in the IT industry. - Computers are improving efficiency and productivity and helping to bring value to customers. - Examples of how technology is making an impact in the business world: - Restaurant and Grocery Store Managers - Courier Dispatchers - Construction Managers - Automotive Mechanics